Cathode active material and lithium-ion electrochemical system thereof
A cathode active material and a Lithium-ion electrochemical system thereof are provided. The lithium-ion cathode material is described by xLiMO 2 *( 1 −x)(Li a M′ 1−a )O y , M and M′ independently comprises one or more metal ions that together have a combined average oxidation state between 3+ or 2+, 1>x≥0.5, 0.75≥a>0, 1≥y≥0.625.
1. A lithium-ion cathode material, wherein the lithium-ion cathode material is described by xLiMO 2 *(1−x)(Li a M′ 1−a )O y , M and M′ independently comprises one or more metal ions that together have a combined average oxidation state between 3+ or 2+, 1>x≥0.5, 0.75≥a>0, 1≥y≥0.625.
2. The lithium-ion cathode material as claimed in claim 1 , wherein M and M′ independently comprises one or more metal ions selected from Ni, Mn, Co, Al, Mg, Nb, Mo, or Zr.
3. The lithium-ion cathode material as claimed in claim 2 , wherein neither M nor M′ comprises metal ion of Co.
4. The lithium-ion cathode material as claimed in claim 2 , wherein M and/or M′ comprises metal ion of Co, and a molar ratio of metal ion of Co to M and V′ is Co/(M+M′)<0.1.
5. The lithium-ion cathode material as claimed in claim 4 , wherein the molar ratio of metal ion of Co to M and M′ is Co/(M+M′)<0.05.
6. The lithium-ion cathode material as claimed in claim 1 , wherein a molar ratio of metal ion Li to M and M′ is Li/(M+M′)>0.95.
7. The lithium-ion cathode material as claimed in claim 6 , wherein the molar ratio of metal ion Li to M and M′ is 1.2>Li/(M+M′)>1.
8. The lithium-ion cathode material as claimed in claim 2 , wherein M and/or M′ comprises metal ion of Ni, and a molar ratio of metal ion of Ni to M and M′ is Ni/(M+M′)>0.5′.
9. The lithium-ion cathode material as claimed in claim 8 , wherein the molar ratio of metal ion of Ni to M and M′ is Ni/(M+M′)>0.7.
10. A Lithium-ion electrochemical system, comprises a cathode electrode, wherein the cathode electrode comprises the lithium-ion cathode material as claimed in claim 1 .
11. The lithium-ion cathode material as claimed in claim 2 , wherein a molar ratio of metal ion Li to M and M′ is Li/(M+M′)>0.95.
12. The lithium-ion cathode material as claimed in claim 3 , wherein a molar ratio of metal ion Li to M and M′ is Li/(M+M″)>0.95.
13. The lithium-ion cathode material as claimed in claim 4 , wherein a molar ratio of metal ion Li to M and M′ is Li/(M+M′)>0.95.
14. The lithium-ion cathode material as claimed in claim 5 , wherein a molar ratio of metal ion Li to M and M′ is Li/(M+M′)>0.95.
15. The lithium-ion cathode material as claimed in claim 3 , wherein M and/or M′ comprises metal ion of Ni, and a molar ratio of metal ion of Ni to M and M′ is Ni/(M+M′)>0.5.
16. The lithium-ion cathode material as claimed in claim 4 , wherein M and/or M′ comprises metal ion of Ni, and a molar ratio of metal ion of Ni to M and M′ is Ni/(M+M′)>0.5.
17. The lithium-ion cathode material as claimed in claim 5 , wherein M and/or M′ comprises metal ion of Ni, and a molar ratio of metal ion of Ni to M and M′ is Ni/(M+M′)>0.5.