Isobaric–Isothermal Polyhedra of Solid Solutions in the Li–Ni–Mn–Co–O System

— Isobaric–isothermal composition polyhedra of solid solutions existing in the Li–Ni–Mn–Co–O system at a temperature of 800°C and oxygen partial pressures in the range 20–100 kPa are constructed in the Li–Ni–Mn–Co tetrahedron using fragmentary experimental data available. Phase equilibria involving LNMCO1, LNMCO2, LNMCO3, and LNMCO4 solid solutions, with the rock salt (Li(Ni,Mn,Co)O), α‑NaFeO 2 ferrite (Li(Ni,Mn,Co)O 2 ), manganite (Li 2 MnO 3 ), and spinel (Li(Ni,Mn,Co) 2 O 4 ) structures, respectively, are analyzed.