A non-aqueous electrolyte secondary battery

Provided is a non-aqueous electrolyte secondary battery which can improve charge-discharge efficiency and capability maitaining rate. Li2-xAxMO3 obtained by replacing lithium in Li2MO3 having a layered structure by an alkali metal having ion radius larger than that of lithium is used as a positive electrode active material. In this Li2-xAxMO3, x satisfies the relation 0alkali metal having the ion radius larger than that of lithium (Li) (for example, sodium (Na) or potassium (K)) and M indicates a transition metal that can be tetravalent. Examples of the transition metal that can be tetravalent indicated by the above-mentioned M include manganese (Mn), molybdenum (Mo), titanium (Ti), platinum (Pt), iridium (Ir), ruthenium (Ru) and the like.