How can we achieve the longevity of lithium-ion batteries?

First of all, too high and too low power states have the most adverse impact on the life of lithium-ion batteries, and the number of charge and discharge cycles is of secondary importance. In fact, the number of rechargeable cycles marked on most of the electrical appliances or batteries sold is measured based on 80% discharge. Experiments have shown that for some laptop lithium-ion batteries, the battery voltage often exceeds the standard voltage by 0.1 volts, that is, from 4.1 volts to 4.2 volts, then the battery life will be halved, and if it is increased by 0.1 volts, the life will be reduced to the original One-third; The long-term low or no power state will make the internal resistance of the battery to the movement of electrons become greater and greater, thus causing the battery capacity to become smaller. NASA set the power consumption of the battery on its Hubble Space Telescope at 10% of the total capacity to ensure that the battery can be repeatedly charged and discharged 100,000 times without needing to be updated. Secondly, temperature also has a greater impact on the life of lithium-ion batteries (mobile phones and other small electronic devices can be ignored). The environment below the freezing point may cause the lithium-ion battery to burn out when the electronic product is turned on, and the overheated environment will reduce the battery capacity. Therefore, if the laptop is used for a long time with an external power supply and the battery is not removed, the battery will be in the high heat discharged by the laptop for a long time. More importantly, the battery will be in a state of 100% for a long time and will soon be scrapped (including me This is how I finished playing with my laptop battery). From the above, we can sum up the following points for precautions to ensure the capacity and life of lithium-ion batteries: • Do not charge the lithium-ion battery to 100% full, let alone use up the power. When the situation permits, try to keep the battery's power near the half-full state, the smaller the charge and discharge range, the better; Li-ion batteries will have dendrites during use, and dendrite breakage will not only cause battery capacity degradation , The life is discounted, and it may pierce the diaphragm and cause the battery to short-circuit and catch fire, causing safety problems. The research group of Professor Liang Jiajie and Chen Yongsheng of Nankai University and the research group of Lai Chao of Jiangsu Normal University jointly proposed a new optimization strategy to solve this problem, and successfully prepared a three-dimensional porous graphene carrier of silver nanowires with a multi-level structure and loaded metal lithium ions. As a composite anode material. This carrier can inhibit the appearance of lithium-ion dendrites, which can realize ultra-high-speed battery charging, which is expected to greatly extend the life of lithium-ion batteries. In recent years, many countries around the world have made important breakthroughs in the design and synthesis of lithium ion anode materials. However, it has not been possible to suppress the appearance of dendrites and the volume expansion of electrodes under high current density charging and discharging of metal lithium ions. Therefore, lithium ion The battery's long life, large capacity, fast charge and fast release are still insurmountable. Depositing metal lithium ions into a porous current collector with a three-dimensional network structure to construct a metal lithium ion composite negative electrode material is currently one of the effective ways to solve the above-mentioned difficulties. Liang Jiajie explained. Based on this understanding, the research group first proposed the selection and optimization strategy of ideal metal lithium ion anode three-dimensional carrier materials to achieve ultra-high current density and ultra-long cycle life. They used the macroscopic three-dimensional network of graphene as the mechanical framework and the two-dimensional network of silver nanowires as the conductive structure. They prepared silver nanowires with hierarchical structure through a low-cost coating and cold-drying method compatible with industrial processing. Porous carrier, and support metal lithium ion as metal lithium ion composite negative electrode material. After testing, the specific capacity of the metal lithium ion composite anode material can reach 2573mAh/g; in the symmetrical battery testing, it is the first time to achieve repeated charging and discharging at a very high current density of 40mAh/cm2 for more than 1000 cycles, and the overpotential is less than 120 millimetres. Volt. It can be seen through electron microscope observation that the multi-level three-dimensional structure carrier can successfully inhibit the growth of lithium ion dendrites in the metal lithium ion negative electrode and the volume change of the electrode even under the cycle conditions of extremely high current charge and discharge. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.