Stabilization of single crystal LiNi_0.90Mn_0.05Co_0.05O₂ via ZrO₂ dual-functional coating enables superior performance for solid-state lithium battery  

Chlorine-rich argyrodites with ultrafastLi-ion conductivities exhibits great potential as solid electrolytes forall-solid-state lithium batteries. However, the poor interfacial stability andslow ion dynamics between Li_5.5PS_4.5Cl_1.5 (Cl1.5)and high nickel layered cathode hinder the achievement of superior batteryperformances. Here, the prepared ZrO₂ coating film was found toperform two functions: enhancing the bulk and interfacial stability of singlecrystal LiNi_0.90Mn_0.05Co_0.05O₂ (NCM911)towards sulfide, and facilitating Li-ion transport rates across the interface.A Li₂ZrO₃ phase with fast Li-ion diffusion rategenerates during cycling and further improve the layered-structure integrity ofNCM911 and interfacial stability toward the Cl1.5 electrolyte, which are due tothe reduction of lattice oxygen release from NCM911 and the isolation of directcontact between the two materials. As a result, these effects enable superiorelectrochemical performances for the ZrO₂-coated NCM911 than thebare sample in Cl1.5-based all-solid-state lithium batteries at varying C-ratesand different operating temperatures. It delivers high initial dischargecapacities of 156.6 mAh g⁻¹ at 2C and retains86.0 % of its capacity after 1000 cycles at room temperature, and displaysan initial discharge capacity of 172.6 mAh g⁻¹ at0.5C under 60 °C and 142.4 mAh g⁻¹ at 0.1C under–20 °C, respectively. This dual-functional surface modification strategyprovides guidelines to stabilize high-nickel cathode in sulfide-basedall-solid-state lithium batteries.