Multilayered Solid Polymer Electrolytes with Sacrificial Coating for Suppressing Lithium Dendrite Growth

The practical application of lithium-metal batteries (LMBs) is hindered by the lithium dendrite formation during cycling. In this work, we report a multilayered solid polymer electrolyte (SPE) formed by sandwiching a comb-chain cross-linker-based network SPE (ConSPE) film with a linear poly­(ethylene oxide) (PEO) SPE coating. Benefiting from the drastically different lithium dendrite resisting properties of the ConSPE and linear PEO SPE, the lithium dendrite growth in the multilayered SPEs could be tuned, with the linear PEO SPE effectively serving as a sacrificial layer to accommodate the lithium dendrite growth. Symmetrical lithium cells with the multilayered SPE exhibited an extended short-circuit time ∼4.1 times that for the single-layer ConSPE at a high current density of 1.5 mA cm–2. Li/LiFePO4 batteries with multilayered SPEs delivered superior cycling performance at extremely high C-rates of 2C and 10C. Our multilayered SPE architecture, therefore, opens up a new gateway for advancing SPE design for future LMBs.