In Situ Polymerization Inhibiting Electron Localization in Hybrid Electrolyte for Room-Temperature Solid-State Lithium Metal Batteries

Hybrid solid electrolytes (HSEs) have attracted much attention due to their advantages as both inorganic and organic polymer electrolytes. However, the organic/inorganic interfacial space charge layer has a great barrier to the transport of Li+ in the HSE. Here, an in situ polymerization layer is proposed on garnet-type particles, working as the coherent region to eliminate the space charge layer at the organic/inorganic interfaces by inhibiting electron localization. The conjugate hybridization of fillers weakens the aggregation of particles, induces the dissociation of Li salt, and provides high-throughput Li+ transport pathways at the ceramics/polymer interface. Furthermore, the continuous Li+ conduction networks are connected by the coherent region between inorganic fillers and polymer chains. The fabricated HSE exhibits a high ionic conductivity of 0.47 mS cm-1 and ion migration numbers of 0.78 at room temperature. The 3D Li//Li systematic battery assembled with the HSE delivers a high critical current density (CCD) of 2.0 mA cm-2. Meanwhile, the 4.5 V NCM811//Li batteries achieve a prolonged operation of 500 cycles at 0.5 C. The Li//LiFePO4 batteries demonstrate superior capacity retention of 96.4% at 1 C after 500 cycles. A model strategy of constructing a coating on garnet-type Li6.4La3Zr1.6Ta0.4O12 (LLZTO) particles is pioneered, working as the coherent region to effectively restrain the electron localization and gain high-throughput Li+ transport pathways at LLZTO/in situ polymerization layer/SSE interface. The interfacial interaction between a 3D Li anode and SSEs provides fast interfacial Li+ transport and significantly improves the interfacial stability to suppress Li dendrites. image