Large-Scale Fabrication of Stable Silicon Anode in Air for Sulfide Solid State Batteries via Ionic-Electronic Dual Conductive Binder.

Abstract

The construction of a continuous ionic/electronic pathway is critical for Si-based sulfide all-solid-state batteries (ASSBs) with the advantages of high-energy density and high-cycle stability. However, a significant impediment arises from the parasitic reaction occurring between the ionic sulfide solid-state electrolyte and electronic carbon additive, posing a formidable challenge. Additionally, the fabrication of electrodes necessitates stringent operational conditions, further limiting practical applicability. Herein, an ionic-electronic dual conductive binder for the fabrication of robust silicon anode under ambient air conditions in the absence of high-cost and air-sensitive sulfide solid-state electrolyte for ASSBs is reported. This binder incorporates in situ reduced silver nanoparticles into a high-strength polymer rich in ether bonds, establishing a conductive pathway for lithium ions and electrons. With the binder-composited Si anode, the half-cell exhibits a remarkable capacity of 1906.9 mAh g^-1 and stable cycling for 500 cycles at a current density of 2 C (4.4 mA cm^-2) under a low stack pressure of 5 MPa. The full cell using Ni_0.9Co_0.075Mn_0.025O₂ (NCM90) exhibits a remark cycling stability within 2000 cycles at 5 C (8 mA cm^-2). This work presents an inspired design of functional binders for large-scale manufacture and mild operation in a low-cost way for Si anodes in ASSBs.