Hongjiu Hu

Solid polymer electrolytes (SPEs) and inorganic solid electrolytes (ISEs) represent the two primary categories of solid-state electrolytes, yet both exhibit inherent limitations.

Polymer-based trench-architectured all-solid-state batteries (ASSLIBs) offer exceptional safety and geometric adaptability for medical devices but suffer from stress-driven mechanical degradation at critical interfaces.

Accurate assessment of the state of health (SOH) of lithium-ion batteries (LIBs) is fundamental to ensuring safe operation. However, due to the complex electrochemical processes during battery operation and the limited availability of training data, accurate estimation of the state of health remains challenging. To address this, this paper proposes a prediction framework based on dual-view voltage signal features and an improved Long Short-Term Memory (LSTM) neural network. By relying solely on readily obtainable voltage signals, the data requirement is greatly reduced; dual-view features, comprising kinetic and aggregated aspects, are extracted based on the underlying reaction mechanisms. To fully leverage the extracted feature information, Scaled Dot-Product Attention (SDPA) is employed to dynamically score all hidden states of the long short-term memory network, adaptively capturing key temporal information. The experimental results based on the NASA PCoE battery dataset indicate that, under various operating conditions, the proposed method achieves an average absolute error below 0.51% and a root mean square error not exceeding 0.58% in state-of-health estimation, demonstrating high predictive accuracy.

Traditional covalently cross-linked solid-state electrolytes exhibit desirable mechanical durability but suffer from limited processability and recyclability due to their permanent network structures. Incorporating dynamic covalent bonds offers a promising solution to these challenges. In this study, we report a reprocessable and recyclable polymer electrolyte based on a dynamic ester bond network, synthesized from commercially available materials. Polyethylene glycol diglycidyl ether (PEGDE) and glutaric anhydride (GA) were cross-linked and cured in the presence of benzyl dimethylamine (BDMA), forming an ester-rich polymer backbone. Subsequently, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) was introduced as a transesterification catalyst to facilitate network rearrangement. Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was incorporated to establish efficient ion transport pathways. By tuning the cross-linking density and catalyst ratio, the electrolyte achieved an ionic conductivity of 1.89 × 10⁻⁵ S/cm at room temperature along with excellent reprocessability.

Understanding the mechanical behaviour of graphite electrode coatings during lithiation is crucial for optimizing high-performance lithium-ion batteries.

Polyethylene oxide (PEO)‐based solid polymer electrolytes are regarded as promising electrolyte materials because of their safety and flexibility. However, low ionic conductivity at ambient temperature and poor mechanical properties have been a hindrance to its development. In this work, we thermally compressed the PEO‐based electrolytes and explored the ionic conductivity, mechanical performance, free volume, and thermal properties of the electrolyte under different thermal pre‐compressing strains (TPC‐strains). The results show that TPC‐strain can significantly improve the ionic conductivity, in‐plane strength, stiffness, and cell specific capacity as well as the mechanical integrity of solid polymer electrolytes within the battery environment. However, it also results in a reduction in the modulus and stiffness of the SPEs in the through‐plane. In particular, applying a TPC‐strain of 10%–20% to the SPEs by thermal compressing may be a suitable option, which can increase the ionic conductivity of the through‐plane to a factor of 3.4 compared with the uncompressed electrolyte, and increase the in‐plane strength by up to 141%, resulting in better mechanical integrity during charging/discharging processes. At the same time, the compression modulus can be maintained at 80% or higher.

Aqueous emulsifiable diphenylmethane diisocyanate (EMDI) can form strong chemical bonds with aqueous adhesives due to the large number of isocyanate (–NCO) groups, which can enhance the mechanical performance of the adhesives. Currently, sodium carboxymethyl cellulose (CMC)–styrene butadiene rubber (SBR) emulsion aqueous bonding agents are widely used in the preparation of anode materials for lithium-ion batteries (LIBs). In this study, EMDI was added to a porous silicon–carbon composite electrode prepared from CMC–SBR, and the evolution of the mechanical properties of the electrode with the EMDI content was first investigated via quasi-static uniaxial tensile and interfacial strength tests. Subsequently, the effect of the EMDI content on the electrochemical properties of the electrodes was analysed by electrochemical impedance spectroscopy (EIS) and constant-current (CC) charge/discharge performance tests. Finally, material characterisation of the electrodes was carried out by Fourier transform infrared (FTIR) spectroscopy and specific surface area (Brunauer–Emmett–Teller (BET)) analysis. The results show that the addition of EMDI with a mass ratio of 10–20% to the CMC–SBR binder can enhance the mechanical performance of the active layer and the interfacial performance between the active layer and the current collector of the silicon–carbon composite electrode; simultaneously, EMDI can significantly reduce the electrochemical impedance of the electrode material and improve the capacity retention of the electrode. This study provides a new solution for modifying silicon–carbon composite electrodes and promotes the development of high-performance silicon–carbon electrodes.

In this research, an oxidized starch/styrene–butadiene rubber system with high capability of absorbing electromagnetic energy was adopted as the main component, the effect of oxidized starch content on the bonding and mechanical properties of aqueous polymer isocyanate (API) after high-frequency curing was evaluated, and the effect mechanisms were explored by combining thermodynamic tests and material characterization methods. Our findings revealed that the addition of oxidized starch enhanced the mechanical properties of API after high-frequency curing and the increase in the amount of oxidized starch enhanced the improvement effect of high-frequency curing on API bonding and mechanical properties. At 5 wt% oxidized starch, high-frequency curing improved API bonding properties by 18.0% and 17.3% under ambient conditions and after boiling water aging, respectively. An increase in oxidized starch content to 25 wt% increased enhancement to 25.1% and 26.4% for the above conditions, respectively. The enhancement effects of tensile strength and Young’s modulus of the API adhesive body were increased from 9.4% and 18.2% to 18.7% and 22.6%, respectively. The potential enhancement mechanism could be that oxidized starch could increase the dielectric loss of API, converting more electromagnetic energy into thermal energy creating more cross-linked structures.