Positive electrode composition for non-aqueous secondary battery and method of producing the same
A method of producing a positive electrode composition for a non-aqueous secondary battery is provided. The method includes heat-treating titanium boride particles at a temperature in a range of 150° C. to 300° C. under an oxygen-containing atmosphere to obtain heat-treated particles and mixing the heat-treated particles with a positive electrode active material comprising lithium transition metal complex oxide particles that comprise nickel in a composition and have a layered structure such that a content of the heat-treated particles relative to the lithium transition metal complex oxide particles is less than or equal to 1.5 mol % in titanium equivalent terms.
1. A method of producing a positive electrode composition for a non-aqueous secondary battery, comprising:
heat-treating titanium boride particles at a temperature in a range of 150° C. to 300° C. under an oxygen-containing atmosphere to obtain heat-treated particles; and
mixing the heat-treated particles with a positive electrode active material comprising lithium transition metal complex oxide particles that comprise nickel in a composition and have a layered structure such that a content of the heat-treated particles relative to the lithium transition metal complex oxide particles is greater than or equal to 0.3 mol % in titanium equivalent terms and less than or equal to 1.5 mol % in titanium equivalent terms,
wherein the lithium transition metal complex oxide particles and the heat-treated particles are each present as substantially independent particles in the positive electrode composition, and
wherein the heat-treated particles are not fused nor integrally sintered with the lithium transition metal complex oxide particles.
2. The method according to claim 1 , wherein the lithium transition metal complex oxide has a composition represented by formula (1):
Li a Ni 1-x-y-z Co x Mn y M 1 z M 2 w O 2 (1),
wherein
1.00≤a≤1.50, 0.00≤x≤0.50, 0.00≤y≤0.50, 0.00≤z≤0.15, 0.000≤w≤0.020, and x+y+z≤0.70;
M 1 is at least one element selected from the group consisting of Al and Mg; and
M 2 is at least one element selected from the group consisting of Ti, Zr, W, Ta, Nb, and Mo.
3. The method according to claim 2 , wherein 0.05≤x≤0.35.
4. The method according to claim 2 , wherein 0.20≤x+y+z≤0.60.
5. The method according to claim 2 , wherein 1.05≤a≤1.25.
6. The method according to claim 1 , wherein the content of the heat-treated particles relative to the lithium transition metal complex oxide particles is greater than or equal to 0.5 mol % and less than or equal to 1.0 mol % in titanium equivalent terms.
7. The method according to claim 1 , wherein a content of an oxygen component in the heat-treated particles is greater than or equal to 1.5 wt % and less than or equal to 2.9 wt %.