Nonaqueous electrolyte secondary battery
View Patent ↗A nonaqueous electrolyte secondary battery disclosed in the present application includes: a positive electrode capable of absorbing and releasing lithium, containing a positive electrode active material composed of a lithium-containing transition metal oxide having a layered crystalline structure; and a negative electrode capable of absorbing and releasing lithium, containing a negative electrode active material composed of a lithium-containing transition metal oxide obtained by substituting some of Ti element of a lithium-containing titanium oxide having a spinel crystalline structure with one or more element different from Ti, wherein a retention of the negative electrode is set to be greater than a retention of the positive electrode, and an irreversible capacity rate of the negative electrode is set to be greater than an irreversible capacity rate of the positive electrode, whereby a discharge ends by negative electrode limitation.
1. A nonaqueous electrolyte secondary battery comprising:
a positive electrode capable of absorbing and releasing lithium, containing a positive electrode active material composed of a lithium-containing transition metal oxide having a layered crystalline structure; and
a negative electrode capable of absorbing and releasing lithium, containing a negative electrode active material composed of a lithium-containing transition metal oxide compound obtained by substituting some of Ti element of a lithium-containing titanium oxide having a spinel crystalline structure with at least Mn,
wherein a discharge ends by negative electrode limitation.
2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the negative electrode active material has an irreversible capacity rate greater than the positive electrode active material.
3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium-containing titanium oxide is Li 4 Ti 5 O 12 .
4. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium-containing transition metal oxide compound obtained by substituting some of Ti element of a lithium-containing titanium oxide having a spinel crystalline structure includes a compound represented as Li 4 Ti 5-w Mn w O 12 (0<w≦0.3).
5. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the positive electrode active material includes at least one compound represented as Li a Ni 1-b-c Co b M c O 2 (0.95≦a≦1.12, 0≦b≦1, 0≦c≦0.50, 0≦b+c≦1, M is at least one element selected from the group consisting of Al, Mn, Ti, Mg, Mo, Y, Zr and Ca).
6. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the positive electrode active material includes at least one selected from the group consisting of:
a compound represented as LiCoO 2 ;
a compound represented as LiNi 1/3 Mn 1/3 Co 1/3 O 2 ; and
a compound represented as LiNi 0.81 CO 0.15 Al 0.04 O 2 .