Low‐Pressure Sulfide All‐Solid‐State Lithium‐Metal Pouch Cell by Self‐Limiting Electrolyte Design

Sulfide-Based all-solid-state lithium metal batteries (ASSLMBs): Sulfide solid electrolytes (SSEs) degrade at Li interfaces, forming mixed conductive interface (MCI) and solid electrolyte interphase (SEI), causing dendrites. A multifunctional composite sulfide electrolyte (M-CSE) combines Li_5.3PS_4.3Cl_1.7 (mechanical) and Li_9.54[Si_0.5Sn_0.5]PSBrO (conductive), enabling self-limiting suppression. ASSLMBs achieve 10 mAh cm⁻², 219 Wh kg⁻¹, 95.04% retention (500 cycles) under ∼30 MPa (Swagelok)/∼2 MPa (pouch).

Abstract

All-solid-state lithium-metal batteries (ASSLMBs) with sulfide solid electrolytes have gained significant attention due to their potential for high energy density and enhanced safety. However, their development has been hindered by rapid lithium dendrite growth, low coulombic efficiency, poor battery rate performance, and poor cycling stability, posing a major obstacle to their commercialization. Herein, a multifunctional composite sulfide electrolyte (M-CSE) is reported that is dynamically stable with lithium metal, promoting uniform Li+ deposition without dendrites. The resulting ASSLMBs exhibit an areal capacity of 10 mAh cm^{− 2}, an energy density of 219 Wh kg⁻¹, and a current density of 3.76 mA cm^{− 2}, with a capacity retention of 95.04% after 500 cycles at 0.5C. The assembled lithium swagelok cell and solid-state lithium-metal pouch cells have relatively low pressures, with the swagelok cell stack pressure ≈30 MPa and the pouch cell stack pressure also ≈2 MPa. More importantly, mass production of ultra-low-pressure pouch cells is realized by 3D printing technology, marking a crucial breakthrough for practical applications.