Long-term cycling quasi-solid-state lithium batteries enabled by 3D nanofibrous TiO2−x@Li anodes and in-situ polymerized gel-electrolytes

Abstract

Lithium (Li) metal battery is a promising next generation energy storage system due to its high energy density, but what hinders its commercialization is the safety hazard of Li-anode, especially under high current densities. Here, we report a dual strategy of using electronic conductive black TiO2−x nanofiber films to construct composite Li-metal anodes with stable 3D networks and applying an in-situ polymerized ionic conductive gel-electrolyte to construct efficient quasi-solid-state Li-batteries (QSSLBs). The 3D nanofibrous Li-anode shows a stable and small nucleation barrier and can run stably (>1600 h) at a high current density of 10 mA/cm2. When matching with high-loading cathodes of LiFePO4, the QSSLBs exhibit excellent long-term cycling stability (>500 cycles) and high-rate capability (>1 C). In addition, the in-situ polymerization strategy can be incorporated with the commercial lamination manufacturing to produce 63-Ah pouch cells of LiFePO4||graphite, which deliver a high initial Coloumbic efficiency, a large energy density at 0.3 C, excellent rate capability from 0.25 to 2 C, and long-term cycling performance at 0.3 and 1 C, showing potential commercial prospects.