Yttrium stabilized argyrodite solid electrolyte with enhanced ionic conductivity and interfacial stability for all-solid-state batteries

The inferior electrochemical stability towards Li anode and relatively low ionic conductivity at room temperature of argyrodite Li6PS5Cl (LPSCl) electrolytes are the intractable challenges for all-solid-state lithium batteries (ASSLBs). Herein, in order to fully address the aforementioned issues, yttrium ion (Y3+) employed as dopant is designed to substitute for P5+ in LPSCl to boost the Li (+) mobility in electrolyte, as well as to ameliorate the interface stability to Li anode. By introducing appropriate Y3+ dopant, the optimized LPSCl-0.02Y electrolyte exhibits high ionic conductivity of 3.3 x 10(-3) S cm(-1) at 25 degrees C, which is 2 times higher than that of the pristine LPSCl (1.5 x 10(-3) S cm(-1)). Benefitting from the high ionic conductivity, LPSCl-0.02Y is endowed with superior inhibition ability of Li dendrite nucleation and growth from Li anode, thereby significantly enhancing the (electro)chemical interfacial stability. Impressively, LiNi0.8Co0.1Mn0.1O2/Li cell with LPSCl-0.02Y electrolyte delivers high initial discharge capacity (165 mA h g(-1) at 0.05C), robust cycling stability (93 mA h g(-1) after 100 cycles) and remarkable rate capability (130 mA h g(-1) at 0.2C). This rationally designed Y-doped LPSCl electrolyte is highly expected to pave the road for the practical application of ASSLBs, and to deepen the understanding of aliovalent substitution mechanism.

Automated summary

By doping yttrium ion (Y3+) into the argyrodite Li6PS5Cl (LPSCl) electrolyte, the Li (+) mobility and interface stability to Li anode are enhanced, leading to high ionic conductivity and improved electrochemical interfacial stability. The Y-doped LPSCl electrolyte shows great potential for practical applications of all-solid-state lithium batteries.