Non-aqueous electrolyte secondary battery

A non-aqueous electrolyte secondary battery comprising:

• square positive electrode plates provided with a positive electrode active material layer formed on a surface of a positive electrode core in each of the positive electrode plates;
• square negative electrode plates provided with a negative electrode active material layer formed on a surface of a negative electrode core in each of the negative electrode plates;
• and
• an outer case storing a non-aqueous electrolyte and a stacked electrode assembly in which the positive electrode plates and the negative electrode plates are stacked interposing separators therebetween,
• wherein each of the width and the height of the positive electrode plates is 100 mm or more, and each of the width and the height of the negative electrode plates is 100 mm or more, and the stacked electrode assembly in which 10 sheets or more of the positive electrode plates and 10 sheets or more of the negative electrode plates are stacked interposing the separators therebetween,
• wherein the positive electrode active material layer comprises a lithium transition-metal composite oxide expressed by Lia(NibCocMnd)MeO2 (1.05≦a≦0.20, 0.3≦b≦3.6, b+c+d=1, 0≦e≦0.05, and M is at least one element selected from the group consisting of Ti, Nb, Mo, Zn, Al, Sn, Mg, Ca, Sr, Zr, and W) as the positive electrode active material,
• wherein the non-aqueous electrolyte contains non-aqueous solvent, and electrolyte salt, and the proportion of a chain carbonate contained in the non-aqueous solvent to the non-aqueous solvent is 50% by volume or more, and the proportion of diethyl carbonate contained in the chain carbonate to the chain carbonate is 70% by volume or more.