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324 results on '"Xiang, Hongfa"'

32. Strategies of Enhancing Ionic Conductivity in Model Solid‐State Electrolyte Li15P4S16Cl3.

Author

Zhang, Jialu, Lou, Chenjie, Dong, Lei, Ping, Weiwei, Xiang, Hongfa, Tang, Mingxue, and Feng, Xuyong

Subjects
SOLID electrolytes, IONIC conductivity, NUCLEAR magnetic resonance, ACTIVATION energy
Abstract

High ionic conductivity is the key point in the development of new solid‐state electrolytes. Herein, a combining strategy of anion (O2−) doping and structure distortion is applied to enhance the Li+ ion conductivity in Li15P4S16Cl3, thus converting the nonionic conductor into fast ionic conductor. Solid‐state 6Li nuclear magnetic resonance analysis shows redistribution of Li+ ions in Li15P4S16Cl3 with O2− doping or local structure distortion via ball milling, indicating energy changes at different lithium sites. As a result, the activation energy is reduced from 0.50 to 0.35 eV for the ball‐milled Li15P4S15.6O0.4Cl3, and the ionic conductivity is enhanced from 10−9 to 10−4 S cm−1. The electrochemical stability of Li15P4S15.6O0.4Cl3 is broadened at the anode side as well. The symmetric cell Li|Li15P4S15.6O0.4Cl3|Li can cycle more than 1000 h with negligible voltage increase. The LiCoO2|Li15P4S15.6O0.4Cl3|Li‐Si all‐solid‐state battery demonstrates an initial capacity of 106 mA h g−1 and retains 92% capacity after 200 cycles at 0.5 C, highlighting excellent rate performance and electrochemical stability. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Low‐Volatile Binder Enables Thermal Shock‐Resistant Thin‐Film Cathodes for Thermal Batteries.

Author

Xie, Yong, Cao, Yong, Zhang, Xu, Dong, Liangping, Liu, Xiaojiang, Cui, Yixiu, Wang, Chao, Cui, Yanhua, Feng, Xuyong, Xiang, Hongfa, and Qie, Long

Subjects
THERMAL batteries, CATHODES, CHAIN scission, CATHODE efficiency, ACRYLIC acid
Abstract

Manufacturing thin‐film components is crucial for achieving high‐efficiency and high‐power thermal batteries (TBs). However, developing binders with low‐gas production at the operating temperature range of TBs (400–550 °C) has proven to be a significant challenge. Here, we report the use of acrylic acid derivative terpolymer (LA136D) as a low‐volatile binder for thin‐film cathode fabrication and studied the chain scission and chemical bond‐breaking mechanisms in pyrolysis. It is shown LA136D defers to random‐chain scission and cross‐linking chain scission mechanisms, which gifts it with a low proportion of volatile products (ψ, ψ = 39.2 wt%) at even up to 550 °C, well below those of the conventional PVDF (77.6 wt%) and SBR (99.2 wt%) binders. Surprisingly, LA136D contributes to constructing a thermal shock‐resistant cathode due to the step‐by‐step bond‐breaking process. This is beneficial for the overall performance of TBs. In discharging test, the thin‐film cathodes exhibited a remarkable 440% reduction in polarization and 300% enhancement in the utilization efficiency of cathode materials, while with just a slight increase of 0.05 MPa in gas pressure compared with traditional "thick‐film" cathode. Our work highlights the potential of LA136D as a low‐volatile binder for thin‐film cathodes and shows the feasibility of manufacturing high‐efficiency and high‐power TBs through polymer molecule engineering. [ABSTRACT FROM AUTHOR]

Published
2024
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34. LaCl3-based sodium halide solid electrolytes with high ionic conductivity for all-solid-state batteries.

Author

Fu, Chengyu, Li, Yifan, Xu, Wenjie, Feng, Xuyong, Gu, Weijian, Liu, Jue, Deng, Wenwen, Wang, Wei, Abeykoon, A. M. Milinda, Su, Laisuo, Zhu, Lingyun, Wu, Xiaojun, and Xiang, Hongfa

Subjects
SUPERIONIC conductors, IONIC conductivity, SOLID electrolytes, SODIUM, X-ray absorption, HALIDES
Abstract

To enable high performance of all solid-state batteries, a catholyte should demonstrate high ionic conductivity, good compressibility and oxidative stability. Here, a LaCl3-based Na+ superionic conductor (Na1−xZrxLa1−xCl4) with high ionic conductivity of 2.9 × 10−4 S cm−1 (30 °C), good compressibility and high oxidative potential (3.80 V vs. Na2Sn) is prepared via solid state reaction combining mechanochemical method. X-ray diffraction reveals a hexagonal structure (P63/m) of Na1−xZrxLa1−xCl4, with Na+ ions forming a one-dimensional diffusion channel along the c-axis. First-principle calculations combining with X-ray absorption fine structure characterization etc. reveal that the ionic conductivity of Na1−xZrxLa1−xCl4 is mainly determined by the size of Na+-channels and the Na+/La3+ mixing in the one-dimensional diffusion channels. When applied as a catholyte, the NaCrO2||Na0.7Zr0.3La0.7Cl4||Na3PS4||Na2Sn all-solid-state batteries demonstrate an initial capacity of 114 mA h g−1 and 88% retention after 70 cycles at 0.3 C. In addition, a high capacity of 94 mA h g−1 can be maintained at 1 C current density. The advancement of sodium halide solid-state electrolytes can propel high-energy-density all-solid-state sodium-ion batteries. Here, the authors present a LaCl3-based electrolyte facilitating rapid Na+ ion conduction along the c-axis diffusion channel, ensuring high capacity even at elevated current densities. [ABSTRACT FROM AUTHOR]

Published
2024
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