Lithium batteries are now ubiquitous in phones, tablets, watches, laptops, electric cars, and many other everyday devices. Even with careful maintenance, they undergo natural aging. What causes this natural aging?
1. The impact of design and manufacturing processes
Material selection is an important part of battery design. Different materials have different performance characteristics, so the performance of completed batteries also varies. The cycling performance of positive and negative electrode materials affects the battery’s cycle life. In formulating the electrodes, attention should be paid to the amounts of positive and negative electrode materials used.
2. The influence of charging cutoff voltage
The amount of lithium removed from NMC materials is directly proportional to the charging cutoff voltage, which means that the higher the charging cutoff voltage, the greater the amount of lithium removed from NMC materials, and correspondingly, the more unstable the structure of the materials. Therefore, it is necessary to choose the charging cutoff voltage reasonably based on the design life of the ternary lithium battery pack.
3. Positive and negative pole compaction
Excessive compaction of the positive and negative electrodes can increase the energy density of the battery cell, but it can also reduce the material’s cycling performance. In theory, greater compaction can cause greater structural damage to the material. Material structure is fundamental to supporting repeated charge-discharge cycles and, therefore, the battery’s service life.