Fusion Bonding Technique for Solvent-free Fabrication of All-solid-state Battery with Ultra-thin Sulfide Electrolyte.

Abstract

For preparing next-generation sulfide all-solid-state batteries (ASSBs), the solvent-free manufacturing process have huge potential for the advantages of economic, thick electrode, and avoidance of organic solvents. However, the dominating solvent-free process is based on the fibrillation of polytetrafluoroethylene, suffering from poor mechanical property and electrochemical instability. Herein, a continuously solvent-free paradigm of fusion bonding technique is developed. A percolation network of thermoplastic polyamide (TPA) binder with low viscosity in viscous state is constructed with Li6PS5Cl (LPSC) by thermocompression (≤5MPa), facilitating the formation of ultrathin LPSC film (≤25μm). This composite sulfide film (CSF) exhibits excellent mechanical properties, ionic conductivity (2.1 mS/cm), and unique stress-dissipation to promote interface stabilization. Thick LiNi0.83Co0.11Mn0.06O2 cathode can be prepared by this solvent-free method and tighly adhered to CSF by interfacial fusion of TPA for integrated battery. This integrated ASSB shows high-energy-density feasibility (>2.5 mAh·cm-2 after 1400 cycles of 9200 hours and run for more than 10 000 hours), and energy density of 390 Wh·kg-1 and 1020 Wh·L-1. More specially, high-voltage bipolar cell (≥8.5V) and bulk-type pouch cell (326 Wh·kg-1) are facilely assembled with good cycling performance. This work inspires commercialization of ASSBs by a solvent-free method and provides beneficial guiding for stable batteries. This article is protected by copyright. All rights reserved.