The electrochemical performance of lithium-ion batteries (LIBs) is plagued by sluggish interfacial kinetics. Fortunately, the Li⁺ solvation structure bridges the bulk electrolyte and interfacial chemistry, providing a pathway for promoting electrochemical kinetics in LIBs. Herein, we improve the interfacial kinetics by tuning the Li⁺ coordination chemistry based on solvent molecular engineering. Specifically, 4-fluorobenzyl cyanide (FBCN), featuring steric hindrance and a weak Lewis basic center, is designed to construct a bulky coordination structure with Li⁺, weakening ion–dipole interaction (Li⁺–solvents) but promoting coulombic attraction (Li⁺–anions) at a normal Li salt concentration. This sterically-controlled solvation chemistry reduces the interfacial barrier and thus contributes to improved rate performance, as demonstrated practically in LiFePO₄//graphite pouch cells. This study provides fresh insights into solvent steric control and coordination chemistry engineering, opening a new avenue for enhancing electrochemical kinetics in LIBs.

中文翻译：

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4-氟苄基氰，一种空间位阻溶剂，可促进锂离子电池中的界面动力学

锂离子电池（LIB）的电化学性能受到缓慢的界面动力学的困扰。幸运的是，Li ⁺溶剂化结构连接了本体电解质和界面化学，为促进LIB中的电化学动力学提供了途径。在此，我们通过基于溶剂分子工程调整Li ⁺配位化学来改善界面动力学。具体而言，4-氟苯甲基氰化物（FBCN）具有空间位阻和弱路易斯碱性中心，旨在与Li ⁺构建庞大的配位结构，削弱离子偶极相互作用（Li ^{+ -}溶剂），但促进库仑吸引力（Li ⁺ –阴离子）在正常的锂盐浓度下。这种空间控制的溶剂化化学降低了界面势垒，从而有助于提高倍率性能，正如 LiFePO ₄ //石墨软包电池中的实际情况所证明的那样。这项研究为溶剂空间控制和配位化学工程提供了新的见解，为增强锂离子电池的电化学动力学开辟了新途径。