公开(公告)号：US20210313563A1

公开(公告)日：2021-10-07

申请号：US16964746

申请日：2020-05-22

Applicant: NINGDE AMPEREX TECHNOLOGY LIMITED

Inventor： Feilong GUO ,  Juan JIN ,  Xinbing CHEN ,  Hongming YU

IPC: H01M4/36 ,  H01M4/505 ,  H01M4/525 ,  H01M4/131 ,  H01M10/0525

Abstract: The present application relates to a cathode and an electrochemical device. The cathode comprises: a cathode current collector; and a cathode active material layer disposed on a surface of the cathode current collector, wherein the cathode active material layer comprises a first particle and a second particle, the first particle comprising a secondary particle composed of a third particle, the third particle being a primary particle, the first particle having an average particle size of 5 μm to 20 μm, the third particle having an average particle size of 200 nm to 700 nm, the second particle comprising a fourth particle and/or a secondary particle composed of the fourth particle, the fourth particle being a primary particle, the second particle having an average particle size of 3 μm to 5 μm, the fourth particle having an average particle size of 800 nm to 5 μm, the first particle being contained in a region close to the cathode current collector, and the second particle being contained in a region away from the cathode current collector. The cathode can significantly improve the rate performance, cycle performance and safety performance of the electrochemical device.

公开(公告)号：US20190178950A1

公开(公告)日：2019-06-13

申请号：US16214746

申请日：2018-12-10

Applicant: NINGDE AMPEREX TECHNOLOGY LIMITED

Inventor： Fei WU ,  Juan JIN ,  Kefei WANG

IPC: G01R31/389 ,  G01R31/3842 ,  G01R31/367

Abstract: The present disclosure relates to the field of battery state monitoring technologies, and in particular, to a battery state monitoring method and apparatus. The method is: monitoring a voltage value and a current value of an output end of a battery; determining a battery impedance value based on the voltage value; calculating an impedance voltage-drop value based on the current value and the battery impedance value; calculating an open circuit voltage of the battery based on the voltage value and the impedance voltage-drop value; when a difference of the open circuit voltage between two consecutive calculations is greater than or equal to a threshold, judging that the battery state is abnormal; and when the difference of the open circuit voltage between two consecutive calculations is determined to be lower than the threshold, updating the battery impedance value based on the voltage value and the current value. By using the foregoing method, the battery state is judged by verifying a relationship between a set threshold and a difference of the open circuit voltage between two consecutive calculations, thereby improving the accuracy of battery safety judgment. A possibility of a safety accident occurring in a battery can be predicted, thereby reducing or avoiding a risk of fire outbreak of a device caused due to a battery safety fault of the device.