Li+ selective transport network-assisted high-performance of garnet-based solid electrolyte for Li metal batteries

Battery systems based on garnet-type solid electrolytes and Li metal anodes coupled with high-specific-capacity cathodes are expected to be the most promising high-energy density solid-state lithium-ion batteries. However, the low critical current density of garnet-type solid electrolytes and their high interface resistance have been the main challenges facing these materials in the application of solid-state batteries. Herein, a low-melting-point metal chloride coating combined with in situ lithiation addresses the key issues of interface contact and growth of Li dendrites. BiCl3 with fluid properties can serve as an "aqueous" interlayer, in situ constructing a 3D cross-linked Li+ selective transport network for Li+ transfer (BiLi3) and electron blockage (LiCl) via thermal lithiation. Consequently, Li/Li symmetric cells can charge/discharge dendrite-free at a high current density of 10.0 mA cm(-2) and stably cycle at 2.5 mA cm(-2) for over 1000 h at room temperature. The Li metal full cells with coated garnet solid electrolyte and LiFePO4 cathode exhibit a 105.5 mA h g(-1) residual capacity at a rate of 4C and 138.8 mA h g(-1) reversible capacity at 1C after 600 cycles. This innovative modification strategy laid the groundwork for future commercial applications of garnet-type solid electrolytes.