Large-scale synthesis of high-quality lithium-graphite hybrid anodes for mass-controllable and cycling-stable lithium metal batteries

Abstract

Lithium (Li) metal is extremely attractive for rechargeable high–energy density batteries, but suffers from uncontrolled dendrite growth, infinite relative volume change and poor solid electrolyte interphase (SEI). Herein, we report large-scale fabrication of lithium−graphite hybrid (LGH) anodes through a facile one-step stirring molten process. Li metal shell is uniformly combined with commercial graphite core forming high-quality LGH anodes. Impressively, the mass loading of Li metal can be precisely controlled in the LGH and avoids vast excess of Li in full cells. Compared to plain Li foil, the as-obtained LGH possesses stable graphite hosts for Li metal and can effectively reduce local current density during stripping/plating process, thus mitigating dendrite formation and stabilizing interface. Consequently, symmetric cell with LGH electrodes exhibit ultra-stable cycling and low polarization even in carbonate electrolytes. The LGH shows stable operation at 5 mA cm−2 for 100 cycles, with a capacity of 1.5 mAh cm−2 and Li utilization of 25% per cycle. Furthermore, the LGH–Li4Ti5O12 prototype cells are further demonstrated with highly improved capacity retention. All these superiorities make the LGH as promising anodes for next-generation high-performance electrochemical energy storage.