Integrated Solid-State Li-Metal Batteries Mediated by 3d Mixed Ionic & Electronic Anodes and Deformable Melt Interphase

The high reactivity of Li-anodes and the easily separated solid-state interface are two hurdles for constructing stable solid-state Li-metal batteries (SSLBs). Herein, we report a 3D mixed ionic & electronic (MIEC) anode with deformable melt interphase of poly(Ɛ-caprolactone) electrolytes that is highly efficient towards constructing stable SSLBs. The anode is fabricated by integrating a Li foil with a 3D MIEC film via a facile hot-rolling process, in which the MIEC frame is composed of Li 0.33 La 0.56 TiO 3 particle attached porous carbon nanofibers. We propose that the chemical reactions between Li 0.33 La 0.56 TiO 3 and Li facilitates Li-nucleation inside the MIEC frame and thus enables fast stress relaxation and reduces volume fluctuations, while the melt interphase works as a binder to integrate the anodes and electrolytes without delamination during cycling. As a result, the LiFePO 4 /Li batteries can run stably at 0.2 C, 0.5 C and 1 C at 45 °C. The SSLBs achieve a capacity of 160 mA h g -1 at 0.2 C with a high-capacity retention of 93.1% after 100 cycles, showing appealing commercial prospect