Lithium dendrite-free and fast-charging for high voltage nickel-rich lithium metal batteries enabled by bifunctional sulfone-containing electrolyte additives

摘要

Lithium dendrites limit the application of lithium metal as anode, and poor interfacial stability restricts the nickel-rich lithium nickel cobalt manganese oxides as cathode. Herein, diphenyl sulfone (DPS) and bis(4-florophenyl) sulfone (BFS) are proposed as bifunctional electrolyte additives. In the Li parallel to LI symmetrical half-batteries, with 0.5 wt % DPS, high cycle stability for 360 h at the current density of 1 mA cm(-2) is realized by forming a dense and smooth LiF-rich solid electrolyte interphase (SEI). In the Li parallel to LiNi0.8Mn0.1Co0.1O2 (NMC811) battery, from the long-term cycle tests at 5C after 500 cycles, the capacity retention loss of 0.05% per cycle is found by addition of 0.5 wt% DPS, which is much lower than that with 0.5 wt% of BFS (0.08%) and no additives (0.16%). Proper content of LIP, Li2SO3 and ROSO2Li caused by DPS are beneficial to form a stable solid electrolyte interphase film for the Li parallel to NMC batteries, which facilitates lithium ion transport, and inhibits electron transfer. Therefore, Li parallel to NMC batteries with additives exhibit longer cycle life, higher capacity retention and better fast charging performance than that without any additive.