Heterogeneous electrolyte membranes enabling double-side stable interfaces for solid lithium batteries

The solid polymer electrolyte (SPE) is one of the most promising candidates for building solid lithium batteries with high energy density and safety due to its advantages of flexibility and light-weight. However, the conventional monolayered electrolytes usually exhibit unstable contacts with either high-voltage cathodes or Li-metal anodes during cell operation. Herein, heterogeneous dual-layered electrolyte membranes (HDEMs) consisting of the specific functional polymer matrixes united with the designed solid ceramic fillers are constructed to address the crucial issues of interfacial instability. The electrolyte layers composed of the high-conductivity and oxidation-resistance polyacrylonitrile (PAN) combined with Li 0.33 La 0.557 TiO 3 nanofibers are in contact with the high-voltage cathodes, achieving the compatible interface between the cathodes and the electrolytes. Meanwhile, the electrolyte layers composed of the high-stability and dendrite-resistance polyethylene oxide (PEO) with Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 nanoparticles are in contact with the Li-metal anodes, aiming to suppress the dendrite growth, as well as avoid the passivation between the PAN and the Li-metal. Consequently, the solid LiNi 0.6 Co 0.2 Mn 0.2 O 2 ||Li full cells based on the designed HDEMs show the good rate and cycling performance, i.e. the discharge capacity of 170.1 mAh g −1 with a capacity retention of 78.2% after 100 cycles at 0.1C and 30 °C. The results provide an effective strategy to construct the heterogeneous electrolyte membranes with double-side stable electrode/electrolyte interfaces for the high-voltage and dendrite-free solid lithium batteries.