A positive electrode active material composition, a positive electrode plate, a battery, and an electric apparatus are described. The positive electrode active material composition includes a first positive electrode active material and a second positive electrode active material, where the first positive electrode active material includes a core Li.sub.aA.sub.bMn.sub.fB.sub.1-fP.sub.1-dR.sub.dO.sub.4-nD.sub.n and a coating layer covering the core. The coating layer comprises one or more of pyrophosphate, phosphate, and carbon. The second positive electrode active material includes a compound LiNi.sub.xCo.sub.yM.sub.1-x-yO.sub.2; and 0.018m+0.003fz0.02m+0.02f is satisfied.

A solid-state electrolyte material includes doped lithium argyrodite of formula of Li.sub.6-2a-bM.sub.aTCh.sub.5-a-bO.sub.aX.sub.1+b; where 0<a0.5; 0<b0.5, M is Zn, Mg, Ca, Sr, Be or a combination of any two or more thereof; T is P, As, Sb, or a combination of any two or more thereof; Ch is S, Se, or a combination thereof; and X is F, Cl, Br, I, or a combination of any two or more thereof.

A solid-state electrolyte material includes doped lithium argyrodite of formula of Li.sub.6-2a-bM.sub.aTCh.sub.5-a-bO.sub.aX.sub.1+b; where 0<a0.5; 0<b0.5, M is Zn, Mg, Ca, Sr, Be or a combination of any two or more thereof; T is P, As, Sb, or a combination of any two or more thereof; Ch is S, Se, or a combination thereof; and X is F, Cl, Br, I, or a combination of any two or more thereof.

A process for preparing a fluorinating reagent from a calcium-containing compound is disclosed. The process bypasses the requirement to form hydrofluoric acid. The fluorinating reagent can be used to prepare high-value fluorochemicals.