7 months, 1 week ago
It has been about 28 years since the first commercial lithium battery was introduced. During this time, the average annual growth rate of its energy density is about 4%. It does not win Moore's Law, and even does not win CPI. Obviously, today, with the continuous improvement of mobile phone performance, it is difficult to really improve the battery life defects. One aspect of the reason is that the capacity uplift potential of the positive and negative materials is limited. For example, lithium ions in lithium cobaltate can only partially escape, otherwise there will be a problem of collapse of the layered structure. It can be said that it is not an easy task to increase the charge cut-off voltage by 0.05V. Other structures such as ternary materials and NCA are similar to lithium cobalt oxide, and the capacity cannot be revolutionized. The biggest significance lies in resource conservation. The negative electrode is now mainly made of graphite, and the development of a new generation of silicon-carbon negative electrode is step by step. The variation of the charge and discharge volume of silicon is very obvious. It seems that some news reports are easy to solve, and actually need to do a lot. In addition to capacity, cycle life (which can be used for several years) and rate performance (fast charge) should also be considered - but these performance indicators often conflict with the capacity of materials, and must be balanced. On the other hand, some components in the battery, such as the casing, current collector, diaphragm, electrolyte, etc., do not provide capacity by themselves, and need to be simplified in weight and volume through reasonable design, but that is not unlimited. This further increases the difficulty of improving the overall energy density. In short, the Nobel Prize is affirmation for the Blazers, but the development of lithium batteries is still a long way. The progress of any advanced industrial product requires hard work, and this is the unchanging truth.