摘要
Ionic conductivity and electro/chemical compatibility of Li_(10)SnP_(2)S_(12) electrolytes play crucial roles in achieving superior electrochemical performances of the corresponding solid-state batteries.However,the relatively low Li-ion conductivity and poor stability of Li_(10)SnP_(2)S_(12) toward high-voltage layered oxide cathodes limit its applications.Here,a Br-substituted strategy has been applied to promote Li-ion conductivity.The optimal composition of Li_(9.9)SnP_(2)S_(11.9)Br_(0.1) delivers high conductivity up to 6.0 mS cm^(−1).7Li static spin-lattice relaxation(T1)nuclear magnetic resonance(NMR)and density functional theory simulation are combined to unravel the improvement of Li-ion diffusion mechanism for the modified electrolytes.To mitigate the interfacial stability between the Li_(9.9)SnP_(2)S_(11.9)Br_(0.1) electrolyte and the bare LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2) cathode,introducing Li_(2)ZrO_(3) coating layer and Li_(3)InCl_(6) isolating layer strategies has been employed to fabricate all-solid-state lithium batteries with excellent electrochemical performances.The Li_(3)InCl_(6)-LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)/Li_(3)InCl_(6)/Li_(9.9)SnP_(2)S_(11.9)Br_(0.1)/Li-In battery delivers much higher discharge capacities and fast capacity degradations at different charge/discharge C rates,while the Li_(2)ZrO_(3)@LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)/Li_(9.9)SnP_(2)S_(11.9)Br_(0.1)/Li-In battery shows slightly lower discharge capacities at the same C rates and superior cycling performances.Multiple characterization methods are conducted to reveal the differences of battery performance.The poor electrochemical performance of the latter battery configuration is associated with the interfacial instability between the Li_(3)InCl_(6) electrolyte and the Li_(9.9)SnP_(2)S_(11.9)Br_(0.1) electrolyte.This work offers an effective strategy to constructing Li_(10)SnP_(2)S_(12)-based all-solid-state lithium batteries with high capacities and superior cyclabilities.
基金
National Key Research and Development Program(2021YFB2500200)
National Natural Science Foundation of China(no.52177214)
China Fujian Energy Devices Science and Technology Innovation Laboratory Open Fund(no.21C-OP202211).
