Decline Mechanism of Graphite/Lithium Metal Hybrid Anode and Its Stabilization by Inorganic-Rich Solid Electrolyte Interface

Thegraphite/lithium metal hybrid anode shows great potential forachieving high-specific-energy lithium batteries. Despite the "deadlithium" problem caused by repeated stripping and depositionof Li component based on a conversion reaction, the degradation mechanism,based on intercalation reaction, of graphite in a hybrid anode isgenerally ignored. In this contribution, through in situ X-ray diffractionand in situ Raman analysis, we reveal that hysteresis and the mixed-phasestate of graphite during deintercalation play a critical role in hybridbattery degradation. On the other hand, we successfully mitigatedgraphite degradation and increased the reversible capacity of thehybrid anode by introducing an inorganic-rich solid electrolyte interface.Remarkably, the hybrid anode (30% higher specific capacity comparedto graphite) exhibits an average coulombic efficiency of 99.11% andretains 96.13% of initial capacity over 120 cycles. This work shedsnew light on the advancement of high-specific-energy lithium secondarybatteries.