Journal of Power Sources最新文献

Aqueous Zinc-Ion Batteries (AZIB), as a promising class of multivalent metal-ion batteries, have garnered attention for their exceptional safety and extremely high theoretical capacity. Despite these advantages, their adoption has been impeded by a notable capacity shortfall relative to Lithium-Ion Batteries (LIB). Addressing this challenge, our research leverages glutamic acid as a chelating agent to craft barium-doped ammonium vanadate nanoflowers through a hydrothermal approach, serving as an innovative AZIB cathode material. The incorporation of barium ions has notably expanded the doping distance from 9.817 Å to 12.900 Å, markedly diminishing the diffusion resistance of Zn²⁺ ions and unveiling a plethora of active sites. These structural enhancements have fostered accelerated ion transport and bolstered redox kinetics. Our fabricated cathode material exhibits exceptional reversibility during the redox transitions between V⁵⁺/V⁴⁺ and V³⁺ and the zinc ion doping process. Utilizing BNVO-3 as the cathode, which presents an ideal crystal configuration, the AZIB achieved near-perfect Coulombic efficiency. Impressively, at a current density of 0.1 A g^-1, it achieved a remarkable peak discharge capacity of 384.91 mAh g^-1. Furthermore, after 1500 cycles at 5A g⁻¹, it maintained an impressive 92.9 % capacity retention. This study heralds a new era for barium-doped vanadium-based AZIB cathodes, characterized by their high stability, reversibility, and capacity.

As the candidate for electrolyte in lithium metal batteries, quasi-solid electrolytes have been affected by the growth of lithium dendrites and the continuous reaction between lithium and electrolyte. Herein, we introduce a quasi-solid electrolyte, ZIF-67@ZIF-8/PVDF-HFP (PHMx), with multi-stage ion transport channels. Additionally, we have developed Zeolitic Imidazolate Frameworks (ZIFs) materials that possess a “cage” structure, which is defined as dual-MC nanoparticles. PVDF-HFP in PHMx serves as mechanical backbone, with dual-MC nanoparticles densely and uniformly distributed within the PVDF-HFP. The synergistic effect of the microporous structure of the PVDF-HFP and that of the dual-MC nanoparticles is utilized to construct multi-stage ion transport channels. PHM9 achieves uniform Li⁺ deposition and inhibits the continuous reaction between lithium and electrolyte. Therefore, PHM9, not only achieves high ionic conductivity of 3.2 × 10⁻³ S cm⁻¹ but also remains stable for 1600 h during Lithium-symmetric cycling. Lithium metal battery, assembled with LiFePO₄ as the cathode material, exhibited stable cycling for 400 cycles at a rate of 0.2 C, demonstrating a capacity retention rate of 86.6 %. Similarly, the lithium metal battery utilizing LiCoO₂ as the cathode material demonstrated stable cycling for 200 cycles at a rate of 0.2 C, exhibiting an impressive capacity retention rate of 96.7 %.

Reversible solid oxide fuel cell (rSOC) is an efficient means of converting chemical energy into electrical energy, offering a promising solution to the imbalance between energy production and consumption. The performance of rSOC in dual-mode operation, utilizing syngas as fuel, is significantly influenced by variations in fuel composition. This study aims to develop an rSOC model using Aspen Plus and the extreme learning machine (ELM) algorithm to evaluate the impact of different fuel compositions on stack performance in both solid oxide fuel cell (SOFC) and solid oxide electrolytic cell (SOEC) modes. Results indicate that the concentrations of H₂ and H₂O are critical for optimal performance in dual-mode operation. Additionally, the water gas shift (WGS) reaction is employed to modify syngas composition for improved performance. When the molar fraction of H₂/H₂O is maintained between 50 % and 60 %, the rSOC achieves a maximum round-trip efficiency of 67.5 %. The optimal syngas composition, with H₂/H₂O/CO₂/CO ratios of 50/5/35/10, can reach a maximum round-trip efficiency of 68.5 %. This study provides theoretical insights into the selection of syngas composition for rSOC in dual-mode operation.

The permeation of H₂ through the membranes of proton exchange membrane water electrolyzers (PEMWEs) is a critical safety concern because of the risk of explosion when H₂ mixes with O₂ at the anode and increases in concentration. In this study, we investigated the modification of the cathode catalyst layer in the membrane electrode assembly as a strategy for achieving the safe operation of PEMWEs. The effects of the polytetrafluoroethylene (PTFE) content and type of ionomer in the cathode catalyst layer on the dissolved H₂ concentration, H₂ crossover, and electrochemical performance were investigated. The lowest dissolved H₂ concentration and H₂ permeation rate were achieved when 8 wt% PTFE was used. Consequently, the H₂ volume fraction in O₂ at the anode was less than 0.88 %. Additionally, using the Nafion ionomer (D520, ion exchange capacity: 1 mmol g⁻¹), H₂ volume fractions of 1.27 % and 1.34 % were obtained at 0.08 and 5 A cm⁻², respectively. These values are below the lower explosion limit of H₂ in O₂ (4 %), implying that the PEMWE can be safely operated in the low-to-high current density range under ambient pressure. These results provide key guidelines for the design of high-safety cathode catalyst layers for PEMWEs.

Governments and research & development (R&D) organizations are actively initiating various programs and research strategies for CO₂ capture, its utilization, and integration with long duration energy storage from renewable sources worldwide. In line with the carbon capture goals, here we report a novel electrochemical Al-CO₂ battery cell, that can simultaneously capture CO₂ and convert it into value-added products, in addition to long-duration energy generation and storage. This innovative approach employs cost-effective Al metal as an anode and an in-house synthesized Ni–Fe based bimetallic double hydroxide catalyst as the cathode, with meticulously optimized compositions and morphologies. We explore the impact of different aqueous electrolyte solutions compositions on the cell performance, demonstrating up to 10 h of stable long duration energy storage with a stable voltage profile. The cell exhibits low polarization even at high current densities of up to 12 mA cm⁻² and maintains stable cycling over 500 h. Through Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray Diffraction and X-ray photoelectron spectroscopy (XPS) analysis, we determined that the discharge product is either NaAlCO₃(OH)₂ or KAlCO₃(OH)₂, distinct from the Al₂(CO₃)₃ typically reported in conventional Al–CO₂ batteries.

Achieving high density while ensuring structural stability and low volume expansion during cycling remains challenging for Si-based anode materials in lithium-ion batteries (LIBs). Herein, we introduce a novel approach to address this issue by developing high tap-density carbon-coated sub-nano-Si-embedded activated carbon (ACSC) anode materials. The resulting ACSC exhibits an ultra-high true density exceeding 0.99 g cm⁻³ and a Si content of 48 % (abbreviated as ACS_0.48C), leading to an impressive volumetric capacity of 2182 mA h cm⁻³. Despite the high tap density and Si content of ACS_0.48C, the ACS_0.48C/artificial graphite (ACS_0.48C/AG) mixture demonstrates a remarkable capacity retention rate of 97.9 % after 200 cycles at 0.5 C, with a modest volume expansion rate of 7.3 % after 50 cycles. The outstanding electrochemical performance can be attributed to the structural stability of ACS_0.48C throughout cycling. The AC scaffold provides a robust mechanical framework to prevent volume expansion and agglomeration of sub-nano-sized Si particles. Furthermore, the homogeneous mixing of amorphous Si and carbon at the atomic level ensures isotropic expansion, thereby enhancing structural stability. The unique structure of ACS_0.48C, combining high tap density and superior cycling performance, offers a solution to the low tap density issue in nanostructures and introduces innovative concepts for the morphology and structural design of Si/C secondary particles.

Transition metal phosphorus trisulfides (MPS₃) are promising sodium-ion battery anode materials because of the unique layered van der Waals structure, diversiform composition, and high theoretical specific capacity. Nevertheless, their practical application is still hindered by poor rate and cycling performance, primarily due to their intrinsic characteristics of low electrical conductivity and susceptibility to pulverization. In this study, hierarchical flower-like MnPS₃ hollow spheres (MnPS₃ HSs) are prepared by phospho-sulfurization of Mn-glycerol solid spheres through Kirkendall effect. The appealing architecture of MnPS₃ HS, characterized by large hollow cavities and three-dimensional vertical nanosheet arrays, results in an increased specific surface area, shortened ion transport distance, and accelerated charge transfer rate. These positive effects collectively enhance the rate and cycling performance of MnPS₃ HS. The prepared MnPS₃ HS affords high specific capacities of 521 and 328 mAh g⁻¹ at 0.1 and 5 A g⁻¹, and an outstanding cycling stability with a retention of 92.6 % after 1000 cycles at 2 A g⁻¹. In the full-cell system, a high capacity retention of 97.5 % after 500 cycles is also maintained. These results provide significant insights into advancing the sodium storage performance of MPS₃-based anodes through the design of a three-dimensional hollow structure.

Reversible protonic ceramic electrochemical cells (R-PCECs) display a vast range of potential applications as an efficient and low-cost technology for the generation of electricity and the production of high-value-added chemicals. However, electrode surface reaction kinetics, especially the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), pose significant challenges to the development of R-PCECs. To achieve the commercialization of R-PCECs, the key lies in the development of an air electrode that possesses both high activity and durability. In this study, a perovskite oxide electrode composed of Pr_0.5Sr_0.5Co_0.9Nb_0.1O_3-δ (PSCN) is designed as a novel air electrode for R-PCECs. During operation, nanoparticles (NPs) with a formula SrCo_0.5Nb_0.5O_3-δ (SCN) are in situ generated on the PSCN framework, thus forming an SCN-coated PSCN (SCN–PSCN) composite with abundant interfaces. These NPs and interfaces notably boost the activity of the composite electrode. As the air electrode for R-PCECs, the SCN–PSCN electrode exhibits excellent performance at 600 °C, in dual modes of fuel cell and electrolysis cell. It achieves a peak power density of 0.89 W cm⁻² and a current density of 1.27 A cm⁻² at 1.3V. Also, the SCN–PSCN air electrode demonstrates stability exceeding 100 h in both FC and EC modes.

Exploration of efficient and robust catalysts for electrocatalytic water splitting is paramount yet challenging for economical hydrogen production. Here, nanoforest-like heterostructures composed of inner NiMoS₄ nanowires and outer Cr-doped Co₃S₄ nanosheets were grown on nickel foams (Cr–Co₃S₄/NiMoS₄) as highly efficient bifunctional electrocatalysts. As a result, Cr–Co₃S₄/NiMoS₄ heterostructures exhibit low overpotentials of 72 mV and 243 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at 10 mA cm⁻², respectively. Moreover, the water electrolyzer assembled by Cr–Co₃S₄/NiMoS₄ as bifunctional electrodes reaches 10 mA cm⁻² at 1.587 V and maintains exceptional stability over 200 h. The experimental and theoretical characterizations collectively unveil that the charge redistribution occurs at the heterointerface between Cr-doped Co₃S₄ and NiMoS₄, resulting in the regulation of both their electronic structures, which optimizes the adsorption of HER intermediates and decreases the energy barrier of determining step for OER. Additionally, the Cr doping and nanoforest-like morphology increase the intrinsic conductivity and the exposure of active sites, collectively improving the water electrolysis efficiency. This finding presents a promising way to construct and adjust the heterojunction engineering for bifunctional electrocatalysts toward water electrolysis.

Ni-Yttria Stabilized Zirconia (Ni-YSZ) cermet electrode is known to perform in CO₂ (+H₂) stream. Introducing H₂ in CO₂ containing streams enables thermochemical reverse water gas shift reaction (rWGS: CO₂ + H₂ → CO + H₂O) at open circuit. Without the application of any bias, the rWGS responds positively to an increase in temperature and concentrations of CO₂ and H₂. Application of bias results in enhancement in CO yield above the rWGS baseline value. With bias, both CO₂ and H₂O electrolysis are enabled. The infiltration of Cu on the Ni-YSZ backbone results in significant improvement of the reaction kinetics and increases H₂ and CO production. Impedance analysis indicates that the kinetic limitation originates from reaction steps with slower time constants with Ni{Cu}_x-YSZ outperforming Ni-YSZ in this aspect. Cu infiltration suppresses particle coarsening typically observed in Ni-YSZ.