Cathode structural design enabling interconnected ionic/electronic transport channels for high-performance solid-state lithium batteries

Abstract

Great achievements have been accomplished for high performance solid-state electrolytes, however, the poor electrode/electrolyte interfacial contact severely impedes the development of solid-state lithium batteries (SSLBs). Herein, we design a 3D structural composite cathode based on cross-linked electrospun LiNi0.5Co0.2Mn0.3O2 (ES-NCM) network and ductile Li+ conductive polymer electrolyte. Improved electrochemical kinetics and intimate interface are realized through infiltrating polymer precursor into ES-NCM network followed by in-situ polymerization. Assembled with Li1.3Al0.3Ti1.7(PO4)3-polyvinylidene fluoride (LATP-PVDF) solid electrolyte, the composite ES-NCM||LATP-PVDF||Li battery exhibits satisfactory electrochemical performance (with an initial discharge capacity of 143.2 mAh g−1 at 0.1C and a capacity retention of 74.0% after 80 cycles) since continuous Li+/e− conduction channels are generated by ES-NCM skeleton and Li+ conductive polymer. Besides, the high areal capacity of 1.19 mAh cm−2 at a high ES-NCM loading of 9.28 mg cm−2 further supports the feasibility of our composite cathode design in the application of high energy-density SSLBs. Additionally, the flexible solid-state pouch cell exhibits excellent electrochemical performance (with a discharge capacity of 131.6 mAh g−1) and reliable safety characteristics under mechanical abuse. This work is anticipated to provide a new perspective in overcoming solid-solid contact issues in SSLBs.