Secondary battery
An exemplary embodiment provides a lithium ion secondary battery using a high energy type anode, which enables long-life operation thereof. A secondary battery according to an exemplary embodiment comprises an electrode element in which a cathode and an anode are oppositely disposed, an electrolytic solution, and an outer packaging body which encloses the electrode element and the electrolytic solution inside; wherein the anode is formed by binding an anode active material, which comprises carbon material (a) that can absorb and desorb a lithium ion, metal (b) that can be alloyed with lithium, and metal oxide (c) that can absorb and desorb a lithium ion, to an anode collector with an anode binder; and wherein the electrolytic solution comprises a liquid medium which is hard to generate carbon dioxide at a concentration of 10 to 80 vol %.
1. A secondary battery, comprising an electrode element in which a cathode and an anode are oppositely disposed, an electrolytic solution, and an outer packaging body which encloses the electrode element and the electrolytic solution inside;
wherein the anode is formed by binding an anode active material, which comprises carbon material (a) that can absorb and desorb a lithium ion, metal (b) that can be alloyed with lithium, and metal oxide (c) that can absorb and desorb a lithium ion, to an anode collector with an anode binder;
wherein the electrolytic solution comprises a phosphoric acid ester compound at a concentration of 40 to 80 vol %, and the phosphoric acid ester is a fluorinated phosphoric acid ester compound that is represented by following formula (1):
wherein in formula (1), x, y and z are each independently 0, 1 or 2, and l, m and n are each independently an integer of 0 to 3, and a, b and c are each independently an integer of 0 to 3, with the proviso that x×l, y×m, z×n, a, b and c are not all together set to be 0;
wherein metal (b) is silicon, and metal oxide (c) is silicon oxide having wholly or partly an amorphous structure and all or part of metal (b) is dispersed in metal oxide (c); and
wherein the anode binder comprises a polyimide or polyamide-imide.
2. The secondary battery according to claim 1 , wherein the fluorinated phosphoric acid ester compound is represented by following formula (2):
O═P(OCH 2 CF 3 ) 3 (2).
3. The secondary battery according to claim 1 , wherein the electrode element has a planar stacking structure.