A POSITIVE ELECTRODE MATERIAL COMPRISING A SOLID ELECTROLYTE FOR SOLID-STATE RECHARGEABLE LITHIUM ION BATTERY WITH A HIGH THERMAL STABILITY

A catholyte destined to be used in a lithium ion solid-state battery, said catholyte comprising: (i) a solid electrolyte powder having a formula: LiSiPGeO, wherein −0.10≤L≤0.10, −0.10≤s≤0.10, −0.10≤p≤0.10, −0.40≤a≤0.40, and 0.00≤x≤0.30, and (ii) a positive electrode active material powder having a formula: LiM′Owhere M′=NiMnCoA with −0.05≤k≤0.05, 0≤x′≤0.40, 0.05≤y′≤0.40, and 0≤z′≤0.05, wherein A is a doping element which is different to Li, M′ and O, said positive active material powder comprising particles having a layered R-3m crystal structure, said catholyte having a D99≤50 μm and an ionic conductivity of at least 1.0×10S/m.