Nonaqueous electrolyte secondary battery
According to one embodiment, a nonaqueous electrolyte secondary battery is provided. The nonaqueous electrolyte secondary battery includes a container member, a negative electrode, a positive electrode, and a nonaqueous electrolyte. The container member is provided with a gas relief structure. The negative electrode includes a negative electrode mixture layer. The negative electrode mixture layer contains a titanium-containing oxide and Mn. Abundance ratios R Ti , R Mn , R A and R B obtained according to an X-ray photoelectron spectroscopy spectrum of the negative electrode mixture layer satisfy the following relational expressions: 0.01≤ R Mn /R Ti ≤0.2 (1); 3≤ R A /R Mn ≤50 (2); and 0.5≤ R A /R B ≤5 (3).
1. A nonaqueous electrolyte secondary battery, comprising:
a container member comprising a gas relief structure;
a negative electrode accommodated in the container member and comprising a negative electrode mixture layer, the negative electrode mixture layer comprising a titanium-containing oxide and Mn;
a positive electrode accommodated in the container member; and
a nonaqueous electrolyte accommodated in the container member,
wherein an X-ray photoelectron spectroscopy spectrum obtained by X-ray photoelectron spectroscopy measurement of the negative electrode mixture layer includes: a peak belonging to Ti; a peak belonging to Mn; a peak belonging to C constituting a CO 3 moiety; and a peak belonging to C constituting a CO 2 moiety and/or a peak belonging to C constituting a CO moiety, and
wherein abundance ratios R Ti , R Mn , R A and R B obtained from the X-ray photoelectron spectroscopy spectrum satisfy the following relational expressions:
0.01≤ R Mn /R Ti ≤0.2 (1);
3≤ R A /R Mn ≤50 (2); and
0.5≤ R A /R B ≤5 (3),
where R Ti is an abundance ratio of Ti, R Mn is an abundance ratio of Mn, and R A is an abundance ratio of C constituting the CO 3 moiety, and
R B is a sum of an abundance ratio R C of C constituting the CO moiety and an abundance ratio R D of C constituting the CO 2 moiety.
2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the titanium-containing oxide comprises lithium titanate having a spinel-type crystal structure.
3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the abundance ratios R Ti , R Mn , R A and R B fall within the following ranges:
0.02≤ R Mn /R Ti ≤0.1;
15≤ R A /R Mn ≤30; and
1≤ R A /R B ≤2.
4. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the nonaqueous electrolyte comprises propylene carbonate.
5. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the container member is a metallic container, and
the metallic container is provided with a gas relief vent as the gas relief structure.
6. The nonaqueous electrolyte secondary battery according to claim 1 , wherein
the container member includes a baggy container made of a laminate film, and
the baggy container comprises:
a heat-seal portion that is located at at least a part of a peripheral edge of the baggy container, and seals a space for accommodating the positive electrode, the negative electrode, and the nonaqueous electrolyte; and
a gas relief vent that is a part of the heat-sealed portion and has heat sealability lower than other parts.