Batteries & Supercaps最新文献

The Cover Feature illustrates an all-solid-state lithium metal battery with polymer electrolytes (SPEs) based on polycarbonate copolymer with spiroacetal rings. The viscoelastic properties of the polycarbonate copolymer enable excellent adhesion to both the lithium anode and the LFP cathode, resulting in stable charge–discharge cycling. X-ray photoemission spectroscopy analysis shows that a moderately thick and LiF-rich cathode electrolyte interphase (CEI) gives rise to stable battery performance. The study reported in the Research Article by Y. Tominaga and co-workers (DOI: 10.1002/batt.202500237) provides design guidelines for novel SPEs aimed at future applications such as flexible devices.

The Front Cover shows how the electrochemical performance of magnesium negative electrodes was boosted without spoiling the favorable compatibility against positive electrodes by integrating a certain multidentate linear oligoether into the conventional ethereal electrolyte solutions. The combined electrochemical and spectroscopic analyses revealed changes in the coordination environments of Mg²⁺ in solution to be responsible for the enhanced interfacial charge-transfer kinetics. More information can be found in the Research Article by T. Mandai (DOI: 10.1002/batt.202500348).

Amidst the prevailing trends of electrification, intelligence, and connectivity, the convergence of new energy vehicles and big data herald transformative opportunities for China's automotive industry. In this context, the estimation of the state of health (SOH) of lithium-ion batteries assumes critical importance for ensuring the safe and efficient operation of electric vehicles. This paper presents a comprehensive exposition of data-driven methodologies for SOH estimation of lithium-ion batteries. It begins with an overview of commonly accepted definitions and the key factors influencing battery SOH, followed by an in-depth exploration of feature engineering—including the processes of feature extraction and selection. The discussion then delves into data-driven approaches to battery SOH management, encompassing both nonprobabilistic and probabilistic models. While numerous methods exist for estimating SOH, each possesses distinct strengths and limitations. Looking ahead, data-driven SOH estimation is poised to evolve toward the integration of multisource data fusion, enhancement through small-sample and transfer learning techniques, incorporation with physical modeling, and expansion across domains. These advancements are anticipated to significantly enhance the precision and dependability of SOH estimation and catalyze the broader deployment of battery technologies across various sectors.

In the quest for sustainable and metal-free energy storage systems, viologen-based materials offer exciting prospects as they are synthetically well accessible and show two reversible electrochemical processes with anion insertion. This study introduces and compares two π-extended viologen–carboxylate materials bearing double zwitterionic backbones as model compounds based on 1,1′-bis(4-carboxyphenyl)-4,4′-bipyridinium ([bcbp]): the neutral [bcbp] as a double zwitterionic molecule (1) and its corresponding (Li)₂[bcbp](ClO₄)₂ disalt (2). The choice of these two materials for our electrochemical studies is motivated by the literature available on their synthesis routes and solid-state properties. Electrochemical tests in lithium half-cells revealed that compound (1) is initially inactive but gradually converts into the electroactive disalt (2) via spontaneous chemical insertion of LiClO₄ from the electrolyte. Compound (2) directly displays the expected reversible two-electron p-type mechanism involving perchlorate anion (de)insertion, while lithium ions act as spectator species. The system delivers stable cycling performance and high coulombic efficiency, supporting the interest of viologen-based zwitterionic salts as host material for negative electrode application in anionic rocking-chair organic batteries. The bipyridinium-bis(carboxylate) radical ((Li)[bcbp]^• (3)) formed during our synthesis optimizations is likewise electrochemically assessed. This fundamental work highlights the tunability of double zwitterionic viologens as molecular platforms to promote optimized p-type negative electrode materials.

Increasing the operating voltage of Li-ion batteries is crucial for enhancing the energy density. However, high-voltage batteries suffer from long-term stability issues. Graphene materials used as electrode additives have previously been shown to improve performance, yet the impact of variations in the graphene materials has not been thoroughly explored. Herein, we explore the effect of graphene oxide (GO) drop-in additives with different lateral sizes in LiNi_0.5Mn_1.5O₄ (LNMO)-positive electrodes. The additive reduces polarization of the LNMO electrode under long-term cycling, leading to stability improvements, with the smaller lateral size proving to be superior.

Accurate and rapid assessment of lithium-ion battery lifetime is essential for predicting remaining lifespan, enabling the selection of appropriate cells for specific applications and determining suitability for second-life use. However, accelerated cyclic aging tests may underestimate a cell's total lifespan due to exaggerated capacity fade that does not occur under real-world conditions. This increased capacity fade is primarily driven by electrolyte motion induced salt inhomogeneity (EMSI) and loss of homogeneity of lithium distribution (HLD). This study investigates the impact of varying charge and discharge currents on capacity loss during accelerated testing in compressed NMC-Gr pouch cells. Most of the capacity loss observed during cycling is fully recoverable after a resting period, with some cells regaining up to 81% of their lost capacity. Contrary to expectations, cells subjected to the highest cycling currents do not exhibit the greatest recoverable capacity loss. This phenomenon can be attributed to the interplay between current and temperature: While higher cycling currents exacerbate EMSI and HLD loss, they simultaneously elevate cell temperature, which mitigates EMSI by weakening polarization, enhancing electrolyte salt diffusion and homogenizing lithium distribution in the anode. Consequently, higher temperatures counteract HLD and EMSI-effect and therefore reduce apparent capacity loss.

This work explores the use of plasma-enhanced chemical vapor deposition (PE-CVD) to deposit a C-coating on binder-free, self-standing electrodes (SSEs). The C-coating consists of a nanocrystalline graphite thin film with crystalline domains measuring ≈14 nm. Regardless of the fabrication pyrolysis temperature of SSE, an increase in crystallite size and a reduction in interlayer space and defects is observed after C-coating and post-treatment at 1500 °C. Pyrolysis of the SSE at 900 °C induce better coverage with the nanographitic layer during PE-CVD , but prevents the development of closed pores during post-treatment at 1500 °C. In contrast, a large number of closed pores form when the SSE is pyrolyzed at 1500 °C. However, no difference in performance is observed between the C-coated SSE pyrolyzed at 900 and 1500 °C and post-annealed at 1500 °C, therefore, lower temperature can be advantageously used for the pyrolysis step. Nevertheless, post-treatment at 1500 °C is necessary to enhance performance. For both materials, the graphite coating minimized the undesirable reactions with the electrolyte, leading to more stable and conductive solid electrolyte interphase, which improves iCE (from 91.0% to 92.5%). A high reversible capacity of 320 mAh g⁻¹ is also obtained, and the higher coating's conductivity is beneficial for rate capability.

Aqueous zinc ion batteries (AZIBs) are regarded as promising candidates for large-scale energy storage due to their intrinsic safety, environmental friendliness, and high energy density. However, their practical deployment is hindered by several challenges, including dendrite growth on the anode, dissolution and structural degradation of cathode materials, and the limitations of conventional separators. To address these issues, various materials have been explored. Among them, electrospun nanofibers have emerged as a particularly attractive solution owing to their controllable nanostructures, large specific surface area, and tunable porosity. Although the application of electrospun nanofibers in AZIBs has expanded rapidly in recent years, a systematic review focusing on this topic remains lacking. To fill this gap, this review comprehensively summarizes the recent progress in leveraging electrospun nanofibers to overcome key limitations in AZIBs. Beginning with the fundamentals and structural design strategies of electrospinning, it highlights advances in their integration into cathodes, anode, and separators. Special emphasis is placed on elucidating the working mechanisms of the nanofibers and the structure–performance correlations between their microstructure and electrochemical properties. Finally, the review outlines future directions and remaining challenges in this field, aiming to offer valuable insights for the rational design of electrospun nanofiber architectures toward more efficient AZIBs.

Porous carbon materials attract great interest due to their wide range of applications in electrochemical energy systems, especially in structured and pore size-tunable carbon materials prepared by template-assisted methods. In this study, a solvent-mediated polymerization-induced self-assembly strategy is designed for the synthesis of hierarchical double-shell-layer porous carbon nanospheres, and screened out the carbon nanospheres N-doped hierarchical meso-microporous carbon spheres (NPCS)-40 with the best morphology and performance by exploring the effects of different 1,3,5-trimethylbenzene contents, different cosolvent ratios, different cosurfactant ratios, as well as different ethylenediamine and resorcinol contents on the carbon nanospheres’ structure. The resulting carbon nanospheres exhibit a specific capacitance of 249 F g⁻¹ in a supercapacitor with a current density of 0.5 A g⁻¹ and 139.4 F g⁻¹ in a symmetric supercapacitor with excellent stability, which is maintained at 117% after 5000 charging and discharging cycles.

Pre-lithiation is an essential step in lithium-ion capacitors (LICs) due to the lack of Li⁺ in both electrodes. The integration of dilithium squarate (Li₂C₄O₄) into the positive electrode of LICs is considered one of the most promising pre-lithiation strategies. Therefore, the ability of Li₂C₄O₄ decomposition products to modify the solid electrolyte interphase has been recently disclosed, although their impact on the positive electrode surface has not been studied yet. In this work, the improvement of the electrochemical performance when Li₂C₄O₄ was included has been investigated by analyzing the surface of activated carbon-based electrodes with and without Li₂C₄O₄ by scanning electron microscopy and X-ray photoelectron spectroscopy. The decomposition of Li₂C₄O₄ leads to the formation of a surface layer on the positive electrode that remains unaltered regardless of the applied potential, as well as after an aging test. Thus, the improved electrochemical performance is attributed to the presence of a pseudocapacitive charge storage mechanism enabled by the surface layer. Lastly, the cells are modified to reveal the main components participating in the surface layer formation. These findings provide valuable insights into the impact, benefits, and limitations of Li₂C₄O₄, which will accelerate the development of other suitable alternative sacrificial salts.