A safe anode-free lithium metal pouch cell enabled by integrating stable quasi-solid electrolytes with oxygen-free cathodes

The severe safety risks arising from notorious lithium dendrites growth and radical oxygen-releasing cathodes in organic liquid electrolytes under abuse conditions, hamper the practice application of lithium metal batteries, especially operated with zero lithium excess (anode-free cells, AFC). Herein, we report a stable quasi-solid electrolyte (QSE) composed of thermoplastic polyurethane and nano-fumed silica aerogels with high mechanical robust, superior hydrophobicity, exceptional thermal and electrochemical stability, as well as the capability to achieving dendrite-free deposition behaviors. Furthermore, the introduction of oxygen-free lithium sulfide as cathode fundamentally avoids the lattice oxygen release from the cathode as well as stable redox free of reactive Li metal and oxygen species, further ensure AFC reliability. As a result, a superior stability of 100 cycles with a high average Coulombic efficiency of over 98.6% can be achieved in the integrative quasi-solid and oxygen-free cathode AFC. As a proof of practical application, such AFC pouch cells with safe configuration exhibits superior reliability against mechanical damage, electrical and thermal abuse condition. This safe configuration of AFC based stable QSE and oxygen-free cathodes paves the way for safe LMBs towards the various application conditions, even under abuse circumstance.