Long-life Quasi-solid-state Anode-Free Battery Enabled by Li Compensation Coupled Interface Engineering.

Initially anode-free Li metal batteries present a promising power source that merges high production feasibility of Li-ion batteries with superb energy capabilities of Li metal batteries. However, their application confronts formidable challenges of extremely short lifespan due to the inadequacy of zero-Li-excess cell configuration against irreversible Li loss. We report a Li compensation coupled interface engineering strategy for realizing long-life quasi-solid-state anode-free batteries. The Li 2 S is utilized as a sacrificial Li supplement to effectively counterbalance irreversible Li loss without damage to cell chemistry. Meanwhile, it demonstrates remarkable efficacy in establishing a robust yet slender inorganic-organic hybrid solid-state interphase for inhibiting cell degradation by dead and dendritic Li. This strategy enables quasi-solid-state anode-free batteries with a long lifespan of 500 cycles. The Ah-scale quasi-solid-state pouch cells, featuring a high-loading LiFePO 4 cathode and lean gel polymer electrolyte, exhibit a high specific energy of 300 Wh kg cell -1 . This achievement translates into an improvement of 46% in gravimetric energy and 94% in volumetric energy compared to LiFePO 4 ||graphite batteries while outperforming LiFePO 4 ||Li metal batteries by 22 - 47% in volumetric energy. Such quasi-solid-state anode-free cells also demonstrate good safety, showcasing remarkable resistance against nail penetration in ambient air without failure, smoke or fire accidents. This article is protected by copyright. All rights reserved.