NOVELTY - A battery is equipped with an anode (21), a cathode (22), and an electrolyte liquid. The anode contains active material(s) comprising complex oxide of lithium, cobalt, nickel, manganese, and magnesium, chromium and/or tungsten, and fluorine, chlorine and/or bromine, complex oxide of lithium, manganese, and cobalt, nickel and/or tungsten, and fluorine, chlorine and/or bromine, or complex oxide of lithium, phosphorus, and cobalt, strontium and/or zirconium. The electrolyte liquid contains a cyclic carbonate ester derivative having a halogen atom.    USE - For portable electronic devices, such as notebook-type portable computers, mobile telephones, and camcorders.    ADVANTAGE - The battery has excellent high-temperature characteristics and chemical stability.    DETAILED DESCRIPTION - A battery is equipped with an anode, a cathode, and an electrolyte liquid. The electrolyte liquid contains a cyclic carbonate ester derivative having a halogen atom. The anode contains active material(s) comprising complex oxide of formula: LifCogNihMnjM1kO(2-m)X1n, LivMn(2-w)M2wOxX2y, or LizM3PO4.    M1=magnesium, aluminum, boron, titanium, vanadium, chromium, iron, copper, zinc, zirconium, molybdenum, tin, calcium, strontium and/or tungsten;    X1,X2=fluorine, chlorine and/or bromine;    f=0.8-1.2;    g,j=0 or more, and less than 1;    h=greater than 0, and 1 or less;    k,n,y=0-0.1;    g+h+j+k=1;    m=-0.1-0.2;    M2=cobalt, nickel, magnesium, aluminum, boron, titanium, vanadium, chromium, iron, copper, zinc, molybdenum, calcium, tin, strontium and/or tungsten;    v,z=0.9-1.1;    w=0-0.6;    x=3.7-4.1;and    M3=cobalt, manganese, iron, nickel, magnesium, aluminum, boron, titanium, vanadium, niobium, copper, zinc, molybdenum, calcium, strontium, tungsten and/or zirconium.    DESCRIPTION OF DRAWING(S) - The figure shows the sectional drawing of the battery. (Drawing includes non-English language text)    Battery can (11)    Insulation board (12)    Anode (21)    Cathode (22)    Separator (23)