Hybrid Ceramic Polymer Electrolytes Enabling Long Cycling in Practical 1 Ah-Class High-Voltage Solid-State Batteries with Li Metal Anode

Abstract

Solid polymer electrolytes offer a safer alternative to organic liquid electrolytes in high-voltage lithium metal batteries, yet challenges remain in achieving adequate cyclability, energy density, scalability, and safety. This study presents the cycling performance of 1 Ah high-voltage lithium polymer batteries featuring a hybrid ceramic polymer electrolyte (HCPE), a lithium metal anode, and a LiNi0.8Mn0.1Co0.1O2 (NMC-811)-based positive electrode. The HCPE stands out for its remarkable mechanical properties, with a Young's modulus exceeding 200 MPa at room temperature, providing robust resistance against dendrite formation. The Li||Li symmetric cells exhibited outstanding performance, cycling for over 1000 hours at a capacity of 2 mAh cm−2, highlighting the exceptional attributes of HCPE. Full cell testing is conducted under practical conditions, utilizing various cell configurations, from coin cells to large pouch cells with a 1 Ah capacity, achieving an energy density of nearly 250 Wh kg−1 and promising cyclability with 80% capacity retention after 110 cycles. The study also investigated thermal runaway characteristics, showing comparability with commercial lithium-ion batteries. This research underscores the scalability and performance of high-voltage lithium metal polymer batteries, advancing their potential for commercial viability.