Active material for lithium ion battery having Mg-containing lithium titanate and lithium ion battery
View Patent ↗It is an object of the present invention to provide an active material for lithium ion battery having an excellent discharge capacity in the potential flat part and a high-performance and long-life lithium ion battery, and particularly to provide a technology of improving voltage flatness. The present invention provides an active material for lithium ion battery represented by a composition formula: Li[Li (1-2x)/3 Mg x Ti (5-x)/3 ]O 4 (0<x<1/2) in which a part of the element of lithium titanate is substituted with Mg, and a lithium ion battery using this active material as a negative electrode active material.
1. An active material for a lithium ion battery represented by a composition formula: Li[Li (1-2x)/3 Mg x Ti (5-x)/3 ]O 4 (0.1<X<1/4), wherein Mg substitutes both Ti and Li.
2. A lithium ion battery comprising an active material for lithium ion battery according to claim 1 , as a negative electrode active material.
3. A lithium ion battery according to claim 2 , further comprising an electrolyte comprising LiPF6 dissolved in a mixed solvent of ethylene carbonate, ethylmethyl carbonate and dimethyl carbonate.
4. A lithium ion battery according to claim 3 , further comprising a separator comprising a polypropylene microporous film having a surface modified by polyacrylate.
5. The active material for a lithium ion battery according to claim 1 , wherein Mg substitutes a part of a six-coordinate 16d site of Li[Li 1/3 Ti 5/3 ]O 4 .
6. The lithium ion battery according to claim 1 , wherein Ti is tetravalent before a first reduction occurs.
7. The lithium battery according to claim 1 , wherein the active material is a single phase of a spinel structure.
8. An active material for a lithium ion battery represented by a composition formula: Li[Li (l-2x)/3 Mg x Ti (5-x)/3 ]O 4 (0.1<x<1/4), wherein Mg that is represented as the molar ratio x replaces a part of Li and Ti.