Patent ID: 6077496
Filing Date: 2000-06-20
Classification: C01G,C01P,H01M,Y02E

Abstract:
A positive electrode active material for use in a nonaqueous secondary cell, the positive electrode active material having a chemical composition represented by the formula Li.sub.a Ni.sub.b M.sub.c O.sub.d, where 0.95.ltoreq.a.ltoreq.1.05; b+c=1; 0<c<0.4; d=2; and M is at least one element selected from the group consisting of Co, Mn, Fe, V, Ti, Al, Sn, Zn, Cu, In, Ga, Si, Ge, Sb, B, P, K, Na, Mg, Ca, Ba, Sr, W, Mo, Nb, Ta, Y and a lanthanide, and which has a median diameter (D.sub.50) of 5 to 30 .mu.m, with a ratio R=D.sub.50 /D.sub.S being 1.5 to 6, wherein D.sub.S is a specific surface area diameter of the formula Ds=6/.rho..multidot.S where .rho. measured in g/cm.sup.3 is the specific gravity measured with a pycnometer and S measured in M.sup.2 /g is the BET specific surface area, said positive electrode active material having an initial capacity of at least 150 mAh/g and experiencing a capacity drop of no more than 18 mAh/g after 15 cycles.