{"id":6036,"date":"2023-05-26T16:53:10","date_gmt":"2023-05-26T08:53:10","guid":{"rendered":"https:\/\/www.ray-tron.com\/?p=6036"},"modified":"2023-07-21T09:45:56","modified_gmt":"2023-07-21T01:45:56","slug":"ele5820","status":"publish","type":"post","link":"https:\/\/www.ray-tron.com\/en\/ele5820\/","title":{"rendered":"The internal structure of lithium battery tabs"},"content":{"rendered":"
The internal structure of lithium-ion batteries is mainly divided into four types according to their production methods: normal structure, middle-ear structure, multi-ear structure, and stacked structure. In the normal structure, there is only one ear for the positive and negative electrodes, which is located at one end of the pole piece and is made by winding; the ear-mid-ear structure has the ear located in the middle of the pole piece, which is generally processed by laser cleaning, interval coating, tape sticking, etc., and the battery has a small internal resistance and good rate performance; the multi-ear wound pole piece has multiple ears, and the position of the ears varies according to the design, the battery resistance is smaller, and the battery rate performance is better; the stacked battery is made by cutting the pole piece into a specific shape and folding the positive and negative electrodes alternately, with one ear in each layer. The battery with this structure has the best rate performance.<\/p>\n
1. Lug center structure<\/p>\n
The position of the tab has a significant impact on the internal resistance and rate of lithium-ion batteries. When the tab is in the middle of the positive and negative electrodes, the internal resistance and rate performance of the battery are the best, and its performance is close to that of the battery with the stacking process. The figure below is a comparison between the tab-center structure and the normal structure. The tab of the normal structure is located at one end of the pole piece, and the tab of the tab-center structure is located in the middle of the battery pole piece.<\/p>\n
The following table shows the difference in battery performance between the two structures. The internal resistance and DC resistance (DCR) of the battery with the same model using the middle-ear structure and the normal structure are quite different. The internal resistance of the normal structure reaches 30m\u03a9, while the internal resistance of the middle-ear structure is only 17m\u03a9; the DCR of the normal structure under the charged state of 50% is 56.6m\u03a9, and that of the middle-ear structure is 47.4m\u03a9. In terms of battery rate performance, the difference in low-rate performance between the two is not large, but the difference in high-rate performance is obvious. The middle-ear structure has the ear in the middle of the pole piece. During the discharge process, the electrons diffuse from the middle to the two ends. When the current is small, the carrier has sufficient ability to pass electrons. However, at high rates, there are too many electrons and the channel is blocked, resulting in poor high-rate performance. At the same time, the pole piece will also generate heat, resulting in poor cycle performance.<\/p>\n