Pub Date : 2025-12-12DOI: 10.1016/j.etran.2025.100527
Chuanjie Wang , Jia Li , Xiaoke Li , Lei Zhang , Siao Zhang , Qinan Yin , Qinghao Zhang , Yongquan Wu , Kaifu Luo , Dengzhou Liu , Aidong Tan , Jianguo Liu
Proton exchange membrane fuel cells (PEMFCs) operating at elevated temperatures (>100 °C) hold promise for simplified water-thermal management compared to conventional 60–85 °C systems. However, the complex interplay of activation polarization, oxygen partial pressure and mass transfer at high temperatures remains unresolved, limiting their practical deployment. Herein, we decode a temperature-dependent trade-off. It governs PEMFCs performance across a wide temperature range (60–100 °C) through operando polarization decomposition, limit current method and a validated multiphysics coupling model, revealing that while rising temperatures reduce the intrinsic total mass transfer resistance (Rtotal) and activation overpotential, these benefits are negated by oxygen partial pressure drop due to accelerated water vaporization-induced gas dilution. To address this bottleneck, we propose an oxygen-enriched air control strategy that dynamically adjusts cathode gas composition, achieving 36 % increase in peak power and 90 mV improvement in voltage (@1.6 A/cm2) at 100 °C. Quantification via game-theoretic analysis shows 67 % performance gain from oxygen compensation and 33 % from activation polarization and Rtotal mitigation. Moreover, there is no sign of accelerated durability degradation compared to air under oxygen-enriched air conditions. This work decouples temperature-dependent polarization mechanisms and provides a transformative pathway for next-generation high-temperature PEMFCs systems.
{"title":"Temperature-dependent performance trade-offs in PEMFCs: A mechanistic study and oxygen-enriched compensation strategy","authors":"Chuanjie Wang , Jia Li , Xiaoke Li , Lei Zhang , Siao Zhang , Qinan Yin , Qinghao Zhang , Yongquan Wu , Kaifu Luo , Dengzhou Liu , Aidong Tan , Jianguo Liu","doi":"10.1016/j.etran.2025.100527","DOIUrl":"10.1016/j.etran.2025.100527","url":null,"abstract":"<div><div>Proton exchange membrane fuel cells (PEMFCs) operating at elevated temperatures (>100 °C) hold promise for simplified water-thermal management compared to conventional 60–85 °C systems. However, the complex interplay of activation polarization, oxygen partial pressure and mass transfer at high temperatures remains unresolved, limiting their practical deployment. Herein, we decode a temperature-dependent trade-off. It governs PEMFCs performance across a wide temperature range (60–100 °C) through operando polarization decomposition, limit current method and a validated multiphysics coupling model, revealing that while rising temperatures reduce the intrinsic total mass transfer resistance (R<sub>total</sub>) and activation overpotential, these benefits are negated by oxygen partial pressure drop due to accelerated water vaporization-induced gas dilution. To address this bottleneck, we propose an oxygen-enriched air control strategy that dynamically adjusts cathode gas composition, achieving 36 % increase in peak power and 90 mV improvement in voltage (@1.6 A/cm<sup>2</sup>) at 100 °C. Quantification via game-theoretic analysis shows 67 % performance gain from oxygen compensation and 33 % from activation polarization and R<sub>total</sub> mitigation. Moreover, there is no sign of accelerated durability degradation compared to air under oxygen-enriched air conditions. This work decouples temperature-dependent polarization mechanisms and provides a transformative pathway for next-generation high-temperature PEMFCs systems.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100527"},"PeriodicalIF":17.0,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-09DOI: 10.1016/j.etran.2025.100526
Qi Li , Zequn Wang , Hanyu Lai , Chunlin Li , Yuchen Pu , Yang Yang , Yongchang Tao , Weirong Chen
The growing scarcity of resources and the prevalence of environmental contamination has led to increased demand for energy trading and transportation. While integrated energy system (IES), as a crucial component in multi-energy coupling and energy conservation and emission reduction, are confronted with significant challenges. In particular, hydrogen energy systems face difficulties in temporal and spatial coupling, wherein pricing mechanisms remain decoupled from geographical delivery constraints and transportation logistics, and supply–demand optimization operates within fragmented frameworks lacking coordinated decision-making. In light of the aforementioned challenges, this paper proposes a trading method of IES considering hydrogen energy trading and transportation. First, this paper establishes an electricity-heat-hydrogen IES model and a transportation network based on the geographical information between IES and hydrogen refueling stations (HRSs). Then, considering that the hydrogen energy transaction between IES and HRSs is affected by hydrogen energy transportation time, distance and price, a two-stage optimization method based on non-cooperative game is proposed. In this game, both IES and HRSs engage in energy transactions with the objective of maximizing revenue. Finally, the effectiveness of the proposed method is verified by the case studies. The results show that the optimal scheduling method considering hydrogen transport can achieve an economic hydrogen trading and transport solution to complete the hydrogen supply to HRSs. The multi-energy transaction was profitable at $1140.07. Compared to conventional fixed-pricing models, the integrated approach achieves significant improvements in system performance, with an 18.57 % reduction in operating costs, a 3.2 % increase in energy utilization efficiency, and up to 22.3 % enhancement in hydrogen trading revenue.
{"title":"Optimal scheduling method for integrated energy system considering hydrogen trading and transportation","authors":"Qi Li , Zequn Wang , Hanyu Lai , Chunlin Li , Yuchen Pu , Yang Yang , Yongchang Tao , Weirong Chen","doi":"10.1016/j.etran.2025.100526","DOIUrl":"10.1016/j.etran.2025.100526","url":null,"abstract":"<div><div>The growing scarcity of resources and the prevalence of environmental contamination has led to increased demand for energy trading and transportation. While integrated energy system (IES), as a crucial component in multi-energy coupling and energy conservation and emission reduction, are confronted with significant challenges. In particular, hydrogen energy systems face difficulties in temporal and spatial coupling, wherein pricing mechanisms remain decoupled from geographical delivery constraints and transportation logistics, and supply–demand optimization operates within fragmented frameworks lacking coordinated decision-making. In light of the aforementioned challenges, this paper proposes a trading method of IES considering hydrogen energy trading and transportation. First, this paper establishes an electricity-heat-hydrogen IES model and a transportation network based on the geographical information between IES and hydrogen refueling stations (HRSs). Then, considering that the hydrogen energy transaction between IES and HRSs is affected by hydrogen energy transportation time, distance and price, a two-stage optimization method based on non-cooperative game is proposed. In this game, both IES and HRSs engage in energy transactions with the objective of maximizing revenue. Finally, the effectiveness of the proposed method is verified by the case studies. The results show that the optimal scheduling method considering hydrogen transport can achieve an economic hydrogen trading and transport solution to complete the hydrogen supply to HRSs. The multi-energy transaction was profitable at $1140.07. Compared to conventional fixed-pricing models, the integrated approach achieves significant improvements in system performance, with an 18.57 % reduction in operating costs, a 3.2 % increase in energy utilization efficiency, and up to 22.3 % enhancement in hydrogen trading revenue.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100526"},"PeriodicalIF":17.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-08DOI: 10.1016/j.etran.2025.100524
Agnes Nakiganda , Martin Lindahl , Callum Henderson , Agustí Egea-Àlvarez , Lars Herre
This paper explores the quantification and forecasting of reserve capacity from electric trains for participation in power system ancillary service markets. We first map train electricity consumption – traction and non-traction – to suitable reserve products, considering operational and regulatory constraints. Using historical data from the Danish railway operator DSB, we estimate the available flexibility for frequency containment reserves, focusing on controllable non-traction loads such as heating and air conditioning. To support market participation, we develop a low-resolution stochastic forecasting model based on conformal prediction, capable of estimating reserve availability for both day-ahead and hour-ahead horizons. Results show that a fleet of approximately 60 active trains can provide up to 10 MW of downward regulation and 1.5 MW of upward regulation from non-traction loads. Additionally, traction power from 25 trains can provide up to 5 MW of upward reserve in certain time periods. The findings demonstrate a viable pathway for integrating electric trains into flexibility markets, offering new revenue opportunities for operators and enhancing grid stability.
{"title":"Quantification and forecasting of reserve capacity from electric trains","authors":"Agnes Nakiganda , Martin Lindahl , Callum Henderson , Agustí Egea-Àlvarez , Lars Herre","doi":"10.1016/j.etran.2025.100524","DOIUrl":"10.1016/j.etran.2025.100524","url":null,"abstract":"<div><div>This paper explores the quantification and forecasting of reserve capacity from electric trains for participation in power system ancillary service markets. We first map train electricity consumption – traction and non-traction – to suitable reserve products, considering operational and regulatory constraints. Using historical data from the Danish railway operator DSB, we estimate the available flexibility for frequency containment reserves, focusing on controllable non-traction loads such as heating and air conditioning. To support market participation, we develop a low-resolution stochastic forecasting model based on conformal prediction, capable of estimating reserve availability for both day-ahead and hour-ahead horizons. Results show that a fleet of approximately 60 active trains can provide up to 10<!--> <!-->MW of downward regulation and 1.5<!--> <!-->MW of upward regulation from non-traction loads. Additionally, traction power from 25 trains can provide up to 5<!--> <!-->MW of upward reserve in certain time periods. The findings demonstrate a viable pathway for integrating electric trains into flexibility markets, offering new revenue opportunities for operators and enhancing grid stability.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100524"},"PeriodicalIF":17.0,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-04DOI: 10.1016/j.etran.2025.100522
Lan-Hao Lou , Xi-Tai Liang , Jiuchun Jiang , Tianjun Lu , Changhong Yu , Chao Chen , Jintao Shi , Feng Ning , Xue Li , Xiao-Guang Yang
Accurate state-of-charge (SOC) estimation for lithium iron phosphate (LFP) batteries remains challenging due to their characteristically flat open-circuit voltage (OCV) profile and pronounced hysteresis effects. Though recent advances have explored mechanical signals to improve estimation accuracy, the inherent non-monotonic force–SOC relationship and thermal expansion effects introduce additional complexities that hinder practical deployment. To address these challenges, we propose a SOC estimation framework that fuses an equivalent circuit model with an equivalent force model, explicitly accounting for both intercalation-induced and thermally induced stress. The proposed dual-model structure is integrated via a dual extended Kalman filter with adaptive weighting. This approach outperforms conventional methods under diverse operating conditions and demonstrates robustness against common error sources. Hardware-in-the-loop validation further confirms the real-time applicability of the proposed framework. This work offers a practical and accurate solution for SOC estimation in LFP batteries used in electric vehicles and energy storage systems.
{"title":"A fused electrical-mechanical model with extended Kalman filter and adaptive weighting for state-of-charge estimation of lithium iron-phosphate batteries","authors":"Lan-Hao Lou , Xi-Tai Liang , Jiuchun Jiang , Tianjun Lu , Changhong Yu , Chao Chen , Jintao Shi , Feng Ning , Xue Li , Xiao-Guang Yang","doi":"10.1016/j.etran.2025.100522","DOIUrl":"10.1016/j.etran.2025.100522","url":null,"abstract":"<div><div>Accurate state-of-charge (SOC) estimation for lithium iron phosphate (LFP) batteries remains challenging due to their characteristically flat open-circuit voltage (OCV) profile and pronounced hysteresis effects. Though recent advances have explored mechanical signals to improve estimation accuracy, the inherent non-monotonic force–SOC relationship and thermal expansion effects introduce additional complexities that hinder practical deployment. To address these challenges, we propose a SOC estimation framework that fuses an equivalent circuit model with an equivalent force model, explicitly accounting for both intercalation-induced and thermally induced stress. The proposed dual-model structure is integrated via a dual extended Kalman filter with adaptive weighting. This approach outperforms conventional methods under diverse operating conditions and demonstrates robustness against common error sources. Hardware-in-the-loop validation further confirms the real-time applicability of the proposed framework. This work offers a practical and accurate solution for SOC estimation in LFP batteries used in electric vehicles and energy storage systems.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100522"},"PeriodicalIF":17.0,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-03DOI: 10.1016/j.etran.2025.100525
Shengyu Tao, Changfu Zou
Internal battery failures often unfold silently, long before any surface signal gives them away, which remains a limitation that has constrained safety engineering for decades. Chen et al.’s recent Nature study breaks this impasse by embedding wireless, ultra-thin sensors directly inside commercial lithium-ion cells, capturing strain and thermal precursors that typically remain invisible until it is too late. In this Commentary, we argue that this work marks a paradigm shift from reactive to proactive battery safety intelligence by enabling autonomous awareness, alert and action. It compels a rethinking of battery management across four dimensions: the need for adaptive data interpretation to handle signal heterogeneity (resulted from different chemistries and operation conditions); the transition of BMS from passive monitoring to proactive maintenance before critical failure onsets; the evolution toward digitalized, distributed, cyber-physical BMS architectures; and the pursuit of other novel silent signals (such as gas signals) for deeper battery degradation insights. Ultimately, the widespread impact of the proposed wireless internal sensing hinges on cost-effective integration at scale and further integration of multiplex internal information fusion and decoupling, paving the way for intrinsically safer, self-aware battery systems in the electrified future.
{"title":"Listening to silent signals: Wireless internal sensing redefines battery safety intelligence","authors":"Shengyu Tao, Changfu Zou","doi":"10.1016/j.etran.2025.100525","DOIUrl":"10.1016/j.etran.2025.100525","url":null,"abstract":"<div><div>Internal battery failures often unfold silently, long before any surface signal gives them away, which remains a limitation that has constrained safety engineering for decades. Chen et al.’s recent Nature study breaks this impasse by embedding wireless, ultra-thin sensors directly inside commercial lithium-ion cells, capturing strain and thermal precursors that typically remain invisible until it is too late. In this Commentary, we argue that this work marks a paradigm shift from reactive to proactive battery safety intelligence by enabling autonomous awareness, alert and action. It compels a rethinking of battery management across four dimensions: the need for adaptive data interpretation to handle signal heterogeneity (resulted from different chemistries and operation conditions); the transition of BMS from passive monitoring to proactive maintenance before critical failure onsets; the evolution toward digitalized, distributed, cyber-physical BMS architectures; and the pursuit of other novel silent signals (such as gas signals) for deeper battery degradation insights. Ultimately, the widespread impact of the proposed wireless internal sensing hinges on cost-effective integration at scale and further integration of multiplex internal information fusion and decoupling, paving the way for intrinsically safer, self-aware battery systems in the electrified future.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100525"},"PeriodicalIF":17.0,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-02DOI: 10.1016/j.etran.2025.100521
Waqas ur Rehman , Siyuan Wang , Liheng Lv , Jonathan W. Kimball , Rui Bo
The widespread adoption of electric vehicles (EVs) and transportation electrification is encumbered by two chief barriers: i) the limited driving range of EVs in the market today and ii) inadequate charging infrastructure support. This paper aims to address the latter bottleneck and proposes a strategic multi-period coordinated planning model to optimally site and size battery energy storage system (BESS) assisted extreme fast charging stations in a highway transportation network and solar systems in a power distribution network. The proposed approach accounts for pre-existing charging stations, the increasing EV penetration levels, decreasing technology costs, and technological advancements in the future and postponing some of the investments. Through the modeling of the spatiotemporal EV charging demand, the transportation and power distribution network coupling, demand charge cost and the integration into mixed integer linear programming framework, this approach optimizes site selection and port sizing across three planning periods. The proposed multi-period planning approach can significantly outperform the conventional forward-myopic method that sequentially solves three separate single-period planning problems. Comprehensive case studies show the proposed planning approach can yield 19 % annual savings in comparison to the benchmark and offer insights to planners regarding the tradeoff between reliability and economics, importance of demand charges reduction, and influence of pre-existing charging stations.
{"title":"Multi-period coordinated planning of XFCS in coupled TN-PDN networks: Integrating demand charge reduction and pre-existing infrastructure","authors":"Waqas ur Rehman , Siyuan Wang , Liheng Lv , Jonathan W. Kimball , Rui Bo","doi":"10.1016/j.etran.2025.100521","DOIUrl":"10.1016/j.etran.2025.100521","url":null,"abstract":"<div><div>The widespread adoption of electric vehicles (EVs) and transportation electrification is encumbered by two chief barriers: i) the limited driving range of EVs in the market today and ii) inadequate charging infrastructure support. This paper aims to address the latter bottleneck and proposes a strategic multi-period coordinated planning model to optimally site and size battery energy storage system (BESS) assisted extreme fast charging stations in a highway transportation network and solar systems in a power distribution network. The proposed approach accounts for pre-existing charging stations, the increasing EV penetration levels, decreasing technology costs, and technological advancements in the future and postponing some of the investments. Through the modeling of the spatiotemporal EV charging demand, the transportation and power distribution network coupling, demand charge cost and the integration into mixed integer linear programming framework, this approach optimizes site selection and port sizing across three planning periods. The proposed multi-period planning approach can significantly outperform the conventional forward-myopic method that sequentially solves three separate single-period planning problems. Comprehensive case studies show the proposed planning approach can yield 19 % annual savings in comparison to the benchmark and offer insights to planners regarding the tradeoff between reliability and economics, importance of demand charges reduction, and influence of pre-existing charging stations.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100521"},"PeriodicalIF":17.0,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-02DOI: 10.1016/j.etran.2025.100523
Rui Tang , Jinyang Dong , Yuefeng Su , Xuebing Han , Fangze Zhao , Yun Lu , Kang Yan , Yi Jin , Ning Li , Lai Chen , Feng Wu
Ensuring the long-term durability of LiFePO4/Graphite (LFP/Gr) pouch cells is essential for their deployment in electric vehicles and stationary energy storage systems. To clarify how multiple external stressors jointly influence failure behavior, this study investigates degradation under coupled high-temperature and over-discharge conditions (45 °C, 1.0 V) in comparison with baseline cycling (25 °C, 2.5 V). A multiscale framework integrating electrochemical diagnostics, structural and interfacial characterization, multimodal imaging, and finite-element modeling was employed to correlate macroscopic performance decay with microscopic failure mechanisms. The coupled condition results in a markedly faster loss of capacity and a nonlinear aging trajectory, in contrast to the nearly linear trend observed under baseline operation. The two stressors show distinct temporal contributions: temperature-driven interfacial breakdown and Fe dissolution appear early and evolve gradually, whereas over-discharge–induced Cu dissolution, graphite disordering, and lithium plating intensify sharply during later stages, establishing a clear sequence of degradation events. Dynamic resistance evolution further confirms staged failure involving SEI reconstruction, lithium inventory depletion, and metal dissolution–related impedance rise. Multimodal imaging reveals pronounced spatial inhomogeneity, including edge-focused lithium accumulation and non-uniform heat and current distribution, highlighting localized regions that are more vulnerable to degradation and safety concerns. Overall, the results provide mechanistic insight into how elevated temperature and over-discharge jointly shape the timing, severity, and spatial distribution of degradation in LFP/Gr pouch cells, and the integrated multiscale analysis framework established here offers a promising basis for extending such coupled-stressor investigations to other chemistries and battery architectures.
{"title":"Inhomogeneous degradation mechanisms in LiFePO4/Graphite pouch cells under temperature and over-discharge coupled accelerated aging","authors":"Rui Tang , Jinyang Dong , Yuefeng Su , Xuebing Han , Fangze Zhao , Yun Lu , Kang Yan , Yi Jin , Ning Li , Lai Chen , Feng Wu","doi":"10.1016/j.etran.2025.100523","DOIUrl":"10.1016/j.etran.2025.100523","url":null,"abstract":"<div><div>Ensuring the long-term durability of LiFePO<sub>4</sub>/Graphite (LFP/Gr) pouch cells is essential for their deployment in electric vehicles and stationary energy storage systems. To clarify how multiple external stressors jointly influence failure behavior, this study investigates degradation under coupled high-temperature and over-discharge conditions (45 °C, 1.0 V) in comparison with baseline cycling (25 °C, 2.5 V). A multiscale framework integrating electrochemical diagnostics, structural and interfacial characterization, multimodal imaging, and finite-element modeling was employed to correlate macroscopic performance decay with microscopic failure mechanisms. The coupled condition results in a markedly faster loss of capacity and a nonlinear aging trajectory, in contrast to the nearly linear trend observed under baseline operation. The two stressors show distinct temporal contributions: temperature-driven interfacial breakdown and Fe dissolution appear early and evolve gradually, whereas over-discharge–induced Cu dissolution, graphite disordering, and lithium plating intensify sharply during later stages, establishing a clear sequence of degradation events. Dynamic resistance evolution further confirms staged failure involving SEI reconstruction, lithium inventory depletion, and metal dissolution–related impedance rise. Multimodal imaging reveals pronounced spatial inhomogeneity, including edge-focused lithium accumulation and non-uniform heat and current distribution, highlighting localized regions that are more vulnerable to degradation and safety concerns. Overall, the results provide mechanistic insight into how elevated temperature and over-discharge jointly shape the timing, severity, and spatial distribution of degradation in LFP/Gr pouch cells, and the integrated multiscale analysis framework established here offers a promising basis for extending such coupled-stressor investigations to other chemistries and battery architectures.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100523"},"PeriodicalIF":17.0,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01DOI: 10.1016/j.etran.2025.100519
Christian Allgäuer, Johannes Huber, Kareem Abo Gamra, Markus Schreiber, Cristina Grosu, Markus Lienkamp
Fast charging is key to increase the convenience and acceptance of battery electric vehicles. However, there are challenges at the battery system level that are not yet sufficiently understood. Due to performance limitations of the vehicle’s thermal management system, thermal gradients occur between the individual battery cells. Since the current distribution between parallel-connected cells cannot be actively controlled, avoiding overload and accelerated degradation is challenging, especially at high currents. In this study, a thermally homogeneous module consisting of two parallel-connected cells and a second module with a 10 °C temperature gradient are tested for 1200 fast charging cycles applying a model-based fast charging protocol. A thermal battery test bench is used to heat and cool the cells before, during, and after the fast charging event according to state-of-the-art thermal management strategies. Cycle life results reveal that the warmer cell in the module with gradient experiences a higher current load at the beginning of life (BoL), with convergent behavior over lifetime. The warmer cell exhibits a higher capacity fade and resistance increase than the other cells. Electrochemical impedance spectroscopy (EIS) shows an increase of the solid electrolyte interface (SEI) and charge transfer (CT) resistance, with the first dominating. Differential voltage analysis (DVA) reveals accelerated cathode degradation for the cell at elevated temperatures. Therefore, reducing thermal gradients and paying closer attention to the cathode when developing future fast-charging protocols is crucial.
{"title":"Model-based fast charging of lithium-ion batteries: Impact of thermal gradients on the degradation of parallel-connected cells","authors":"Christian Allgäuer, Johannes Huber, Kareem Abo Gamra, Markus Schreiber, Cristina Grosu, Markus Lienkamp","doi":"10.1016/j.etran.2025.100519","DOIUrl":"10.1016/j.etran.2025.100519","url":null,"abstract":"<div><div>Fast charging is key to increase the convenience and acceptance of battery electric vehicles. However, there are challenges at the battery system level that are not yet sufficiently understood. Due to performance limitations of the vehicle’s thermal management system, thermal gradients occur between the individual battery cells. Since the current distribution between parallel-connected cells cannot be actively controlled, avoiding overload and accelerated degradation is challenging, especially at high currents. In this study, a thermally homogeneous module consisting of two parallel-connected cells and a second module with a 10<!--> <!-->°C temperature gradient are tested for 1200 fast charging cycles applying a model-based fast charging protocol. A thermal battery test bench is used to heat and cool the cells before, during, and after the fast charging event according to state-of-the-art thermal management strategies. Cycle life results reveal that the warmer cell in the module with gradient experiences a higher current load at the beginning of life (BoL), with convergent behavior over lifetime. The warmer cell exhibits a higher capacity fade and resistance increase than the other cells. Electrochemical impedance spectroscopy (EIS) shows an increase of the solid electrolyte interface (SEI) and charge transfer (CT) resistance, with the first dominating. Differential voltage analysis (DVA) reveals accelerated cathode degradation for the cell at elevated temperatures. Therefore, reducing thermal gradients and paying closer attention to the cathode when developing future fast-charging protocols is crucial.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100519"},"PeriodicalIF":17.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.etran.2025.100518
Markus Schreiber, Lukas Leonard Köning, Georg Balke, Kareem Abo Gamra, Jonas Kayl, Brian Dietermann, Raphael Urban, Cristina Grosu, Markus Lienkamp
In response to the growing demand for electric vehicles, ensuring the longevity of traction batteries has become a central focus of scientific research. While most aging studies rely on accelerated aging testing with tightened stress factors, real-world battery operation reveals fundamentally different load profiles and aging conditions. To disclose the gap between the laboratory and the real-world application, we collected and assessed almost 2600 stress factor combinations from 201 different calendar and cycle aging studies. Moreover, we gathered and analyzed vehicle data from over 72 000 km of everyday usage of seven vehicles in public road traffic in Germany and extracted the related battery-specific load spectra. The stress factor combinations chosen in the literature show a trend towards high temperatures and state of charges (SOCs) during storage in calendar aging studies. In contrast, cycle aging tests are predominantly performed at full depth of discharge (DOD) or elevated average SOC levels, with current rates of primarily at 25 °C or slightly elevated temperatures. Contrary to this, the field data analysis reveals the following main findings: Driving events rarely exceed 30 km in distance or 40 min in duration, with an average driving speed of 61.1 km h. This leads to average current rates of 0.2 C in discharging and 0.1 C in charging direction and average cycle depths of less than 30%, while the average battery pack temperature ranges around 17 °C. Comparing laboratory test conditions with stress conditions in field applications reveals three major discrepancies: First, the stress levels applied are substantially higher than the stresses acting in real-world operation. Second, the dynamic load characteristic of real-world vehicle operation is rarely reflected; most studies work with synthetic constant current load cycles. Third, intermediate rest periods, which are predominant in real-world use, are omitted in most studies. This raises concerns about the transferability and applicability of findings from accelerated aging tests to automotive real-world applications.
为了应对日益增长的电动汽车需求,确保牵引电池的寿命已成为科学研究的中心焦点。虽然大多数老化研究依赖于收紧应力因素的加速老化测试,但实际电池运行显示出完全不同的负载分布和老化条件。为了揭示实验室与实际应用之间的差距,我们收集并评估了来自201个不同日历和周期衰老研究的近2600个压力因子组合。此外,我们收集并分析了7辆汽车在德国公共道路交通中超过72000公里的日常使用数据,并提取了相关的电池特定负载谱。在历法老化研究中,文献中选择的应力因子组合显示了在储存过程中高温和电荷状态(soc)的趋势。相比之下,循环老化测试主要在全放电深度(DOD)或平均SOC水平升高的情况下进行,在25°C或稍微升高的温度下,当前速率主要为±1C。与此相反,现场数据分析揭示了以下主要发现:驾驶事件的距离很少超过30公里或持续时间超过40分钟,平均驾驶速度为61.1 km h−1。这导致放电时的平均电流率为- 0.2 C,充电时的平均电流率为0.1 C,平均循环深度小于30%,而电池组的平均温度范围在17°C左右。将实验室测试条件与现场应用的应力条件进行比较,可以发现三个主要差异:首先,所施加的应力水平大大高于实际操作中的应力水平。二是实际车辆运行的动载荷特性很少得到体现;大多数研究都是在合成恒流负载循环下进行的。第三,大多数研究忽略了在实际应用中占主导地位的中间休息期。这引起了人们对加速老化试验结果在汽车实际应用中的可转移性和适用性的关注。
{"title":"Lab-to-field gap in battery aging studies: Mismatch of operating conditions between laboratory environments and real-world automotive applications","authors":"Markus Schreiber, Lukas Leonard Köning, Georg Balke, Kareem Abo Gamra, Jonas Kayl, Brian Dietermann, Raphael Urban, Cristina Grosu, Markus Lienkamp","doi":"10.1016/j.etran.2025.100518","DOIUrl":"10.1016/j.etran.2025.100518","url":null,"abstract":"<div><div>In response to the growing demand for electric vehicles, ensuring the longevity of traction batteries has become a central focus of scientific research. While most aging studies rely on accelerated aging testing with tightened stress factors, real-world battery operation reveals fundamentally different load profiles and aging conditions. To disclose the gap between the laboratory and the real-world application, we collected and assessed almost 2600 stress factor combinations from 201 different calendar and cycle aging studies. Moreover, we gathered and analyzed vehicle data from over 72<!--> <!-->000 km of everyday usage of seven vehicles in public road traffic in Germany and extracted the related battery-specific load spectra. The stress factor combinations chosen in the literature show a trend towards high temperatures and state of charges (SOCs) during storage in calendar aging studies. In contrast, cycle aging tests are predominantly performed at full depth of discharge (DOD) or elevated average SOC levels, with current rates of primarily <span><math><mrow><mo>±</mo><mn>1</mn><mspace></mspace><mtext>C</mtext></mrow></math></span> at 25<!--> <!-->°C or slightly elevated temperatures. Contrary to this, the field data analysis reveals the following main findings: Driving events rarely exceed 30<!--> <!-->km in distance or 40<!--> <!-->min in duration, with an average driving speed of 61.1 km h<span><math><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. This leads to average current rates of <span><math><mo>−</mo></math></span>0.2 C in discharging and 0.1 C in charging direction and average cycle depths of less than 30%, while the average battery pack temperature ranges around 17<!--> <!-->°C. Comparing laboratory test conditions with stress conditions in field applications reveals three major discrepancies: First, the stress levels applied are substantially higher than the stresses acting in real-world operation. Second, the dynamic load characteristic of real-world vehicle operation is rarely reflected; most studies work with synthetic constant current load cycles. Third, intermediate rest periods, which are predominant in real-world use, are omitted in most studies. This raises concerns about the transferability and applicability of findings from accelerated aging tests to automotive real-world applications.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100518"},"PeriodicalIF":17.0,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-29DOI: 10.1016/j.etran.2025.100520
Zixuan Wang , Linhao Fan , Chasen Tongsh , Siyuan Wu , Zhengguo Qin , Qing Du , Kui Jiao
The pursuit of high-durable low-Pt proton exchange membrane fuel cells (PEMFCs) is fundamentally limited by insufficient understanding of carbon corrosion mechanisms and associated secondary degradation pathways. Here, we employ a coupled operando-ex situ diagnostic approach to deconvolute degradation mechanisms in low-Pt PEMFCs under simulated startup-shutdown conditions. Synchronised monitoring of polarisation curves and electrochemical impedance spectroscopy reveals that charge transfer impedance is the primary factor constraining electrochemical activity and overall cell performance. The fractional contributions of key degradation mechanisms (carbon corrosion, ionomer degradation, Ostwald ripening, and catalyst loss) to electrochemical surface area (ECSA) degradation are quantitatively decoupled. Quantitative mechanistic partitioning reveals ionomer degradation accounts for ∼44.59 % of ECSA loss, surpassing carbon corrosion contributions (∼32.97 %) and overshadowing Ostwald ripening/catalyst loss effects in low-Pt PEMFC. In contrast, carbon corrosion (∼41.56 %) dominated degradation in conventional high-Pt PEMFCs, highlighting a shift in degradation hierarchy as Pt loading is reduced. Advanced scanning electron microscopy, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectroscopy elucidate that spatially uniform ionomer degradation across the low-Pt catalyst layer geometrically amplifies its detrimental impact on the active site. This work highlights the degradation hierarchy in low-Pt PEMFCs, which can provide new references for the design of durable low-Pt electrodes.
{"title":"Homogeneous ionomer degradation dominates electrochemical surface area loss in low-Pt PEMFCs under carbon corrosion conditions","authors":"Zixuan Wang , Linhao Fan , Chasen Tongsh , Siyuan Wu , Zhengguo Qin , Qing Du , Kui Jiao","doi":"10.1016/j.etran.2025.100520","DOIUrl":"10.1016/j.etran.2025.100520","url":null,"abstract":"<div><div>The pursuit of high-durable low-Pt proton exchange membrane fuel cells (PEMFCs) is fundamentally limited by insufficient understanding of carbon corrosion mechanisms and associated secondary degradation pathways. Here, we employ a coupled operando-ex situ diagnostic approach to deconvolute degradation mechanisms in low-Pt PEMFCs under simulated startup-shutdown conditions. Synchronised monitoring of polarisation curves and electrochemical impedance spectroscopy reveals that charge transfer impedance is the primary factor constraining electrochemical activity and overall cell performance. The fractional contributions of key degradation mechanisms (carbon corrosion, ionomer degradation, Ostwald ripening, and catalyst loss) to electrochemical surface area (ECSA) degradation are quantitatively decoupled. Quantitative mechanistic partitioning reveals ionomer degradation accounts for ∼44.59 % of ECSA loss, surpassing carbon corrosion contributions (∼32.97 %) and overshadowing Ostwald ripening/catalyst loss effects in low-Pt PEMFC. In contrast, carbon corrosion (∼41.56 %) dominated degradation in conventional high-Pt PEMFCs, highlighting a shift in degradation hierarchy as Pt loading is reduced. Advanced scanning electron microscopy, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectroscopy elucidate that spatially uniform ionomer degradation across the low-Pt catalyst layer geometrically amplifies its detrimental impact on the active site. This work highlights the degradation hierarchy in low-Pt PEMFCs, which can provide new references for the design of durable low-Pt electrodes.</div></div>","PeriodicalId":36355,"journal":{"name":"Etransportation","volume":"27 ","pages":"Article 100520"},"PeriodicalIF":17.0,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}