POSITIVE ELECTRODE ACTIVE MATERIAL AND SECONDARY BATTERY

    公开(公告)号:US20220006082A1

    公开(公告)日:2022-01-06

    申请号:US17291463

    申请日:2019-11-07

    Abstract: A positive electrode active material with high capacity and excellent charging and discharging cycle performance for a lithium-ion secondary battery is provided. The positive electrode active material contains lithium, cobalt, and oxygen, and the spin density attributed to a bivalent cobalt ion and a tetravalent cobalt ion is within a predetermined range. It is preferable that the positive electrode active material further contain magnesium. An appropriate magnesium concentration is represented as a concentration with respect to cobalt. It is also preferable that the positive electrode active material further contain fluorine.

    METHOD FOR MANUFACTURING POSITIVE ELECTRODE ACTIVE MATERIAL, AND SECONDARY BATTERY

    公开(公告)号:US20210028456A1

    公开(公告)日:2021-01-28

    申请号:US17036740

    申请日:2020-09-29

    Abstract: A positive electrode active material has a small difference in a crystal structure between the charged state and the discharged state. For example, the crystal structure and volume of the positive electrode active material, which has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of approximately 4.6 V, are less likely to be changed by charging and discharging as compared with those of a known positive electrode active material. In order to form the positive electrode active material having the pseudo-spinel crystal structure in the charged state, it is preferable that a halogen source such as a fluorine and a magnesium source be mixed with particles of a composite oxide containing lithium, a transition metal, and oxygen, which is synthesized in advance, and then the mixture be heated at an appropriate temperature for an appropriate time.

    METHOD FOR MANUFACTURING POSITIVE ELECTRODE ACTIVE MATERIAL, AND SECONDARY BATTERY

    公开(公告)号:US20200176770A1

    公开(公告)日:2020-06-04

    申请号:US16624319

    申请日:2018-06-14

    Abstract: A positive electrode active material has a small difference in a crystal structure between the charged state and the discharged state. For example, the crystal structure and volume of the positive electrode active material, which has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of approximately 4.6 V, are less likely to be changed by charging and discharging as compared with those of a known positive electrode active material. In order to form the positive electrode active material having the pseudo-spinel crystal structure in the charged state, it is preferable that a halogen source such as a fluorine and a magnesium source be mixed with particles of a composite oxide containing lithium, a transition metal, and oxygen, which is synthesized in advance, and then the mixture be heated at an appropriate temperature for an appropriate time.

    POSITIVE ELECTRODE ACTIVE MATERIAL, METHOD FOR MANUFACTURING POSITIVE ELECTRODE ACTIVE MATERIAL, AND SECONDARY BATTERY

    公开(公告)号:US20180013130A1

    公开(公告)日:2018-01-11

    申请号:US15638449

    申请日:2017-06-30

    Abstract: A positive electrode active material which can improve cycle characteristics of a secondary battery is provided. Two kinds of regions are provided in a superficial portion of a positive electrode active material such as lithium cobaltate which has a layered rock-salt crystal structure. The inner region is a non-stoichiometric compound containing a transition metal such as titanium, and the outer region is a compound of representative elements such as magnesium oxide. The two kinds of regions each have a rock-salt crystal structure. The inner layered rock-salt crystal structure and the two kinds of regions in the superficial portion are topotaxy; thus, a change of the crystal structure of the positive electrode active material generated by charging and discharging can be effectively suppressed. In addition, since the outer coating layer in contact with an electrolyte solution is the compound of representative elements which is chemically stable, the secondary battery having excellent cycle characteristics can be obtained.

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