In lithium-ion batteries, electrolyte is an important medium for ion transport. On the one hand, the content and composition of electrolyte in the cell have a significant impact on the comprehensive performance of the cell. On the other hand, electrolyte decomposition, deterioration and excessive consumption of electrolyte is also one of the important reasons for lithium-ion battery failure; In addition, with the continuous development of battery technology, batteries will gradually shift from liquid batteries to mixed solid-liquid batteries and even all solid-state batteries. At this time, the liquid content in batteries is the key standard to distinguish the three, and also an important factor affecting the safety of batteries. Testing whether the battery contains liquid, how much liquid it contains, and what components the liquid contains is of great significance for battery failure analysis and the development of the next generation of solid state batteries.

The report discussed from the above three aspects, focusing on the quantitative test of electrolyte content in the cell, and introduced the test method based on standard solution dilution developed by Veilan New Energy and its partners. The method is used to test the liquid content of the cell, and the error of the electrolyte content can be controlled below 2% relative to the quality of the whole cell. The method is currently in the group standard application stage, and the first draft of the standard is expected to be formed and published by the end of December.

In the future, Welion New Energy will also continue to develop qualitative and quantitative characterization methods of electrolyte in cell, laying a foundation for the development of high-performance solid-state lithium batteries in the future.