Electrode assembly, secondary battery, battery module, battery pack, and electric device

• Main Authors: HE XIAONING, XUE WENWEN, ZOU JIELIANG, LIU CHENGYONG, ZHONG CHENGBIN
• Format: Patent
• Language: Chinese; English
• Published: 27.10.2023
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The invention provides an electrode assembly, a secondary battery, a battery module, a battery pack and a power utilization device, the electrode assembly comprises a positive pole piece and a negative pole piece containing a positive active material, the positive pole piece is provided with more than one positive bending part and more than one positive straight part connected with the positive bending part, at least one positive electrode bending part in the positive electrode plate is a first bending part, and at least one part of the positive electrode active material of the first bending part is provided with a polymer coating layer capable of blocking migration of active ions; and the ratio of the ionic conductivity lambda1 of the first bent part to the ionic conductivity lambda2 of the positive straight part satisfies 0 < = lambda1/lambda2 < 1. The safety performance of the secondary battery can be enhanced. 本申请提供一种电极组件、二次电池、电池模块、电池包及用电装置，所述电极组件包括含有正极活性材料的正极极片和负极极片，所述正极极片具有一个以上的正极弯折部和一个以上的与所述正极弯折部相连的正极平