Unveiling the role of lithiophilic sites denseness in regulating lithium ion deposition

The construction of lithiophilic sites is an effective way to achieve uniform lithium(Li)ion deposition for stably cycling Li metal batteries.However,in-depth investigations involving lithiophilic sites denseness(LSD)in impacting Li ion deposition remain unknown.Herein we propose an insight into this issue by probing the effect of LSD on determining the Li ion deposition.Experimental characterization and theoretical simulation demonstrate that rational LSD plays a vital role in both Li nucleation and the subsequent Li ion plating behaviors.By tailoring the LSD from low to high,the accompanied Li nucleation overpotentials continuously decrease.Additionally,the Li ion mobility increases first and then weakens in the subsequent Li ion plating stage.Consequently,the Li metal with a moderate LSD allows a dendritefree morphology and satisfactory long-term cycling performances.This work affords a deeper fundamental understanding of lithiophilic chemistry that directs the development of efficient strategies to realize dendrite-free Li metal batteries.

基于全同源策略构建低界面阻抗的柔性固态锂离子电池

固态锂离子电池被认为是可穿戴电子设备的理想储能器件.然而,高的电极/电解质界面阻抗仍是该领域一个严峻的挑战,尤其在弯曲变形条件下.本文提出全同源策略,利用热塑性聚氨酯作为固态电解质和电极的离子导电框架,构建具有低界面阻抗的柔性固态锂离子电池.实验结果表明,聚氨酯中-C=O、-NH和-C-O-C-等功能基团有助于锂离子传输.利用该特性,制备出具有高柔韧性和离子电导率的聚氨酯基固态电解质,以及具有优异柔韧性的复合电极,其即使在不同形变下仍能保持良好的电化学性能.在此基础上,成功组装了全同源的柔性固态锂离子电池,其表现出更低的界面阻抗和更优异的电化学性能.这种全同源策略为柔性固态电池的设计提供了一种新思路.