Chinese scholars have proposed new methods to inhibit the growth of lithium dendrites, can it improve the life and safety of lithium-ion batteries?
With the rapid development of portable electronic devices and electric vehicles, people are more concerned about the safety of lithium-ion batteries, in addition to pursuing the large capacity and charging and discharging speed of lithium-ion batteries. The repeated explosions of lithium-ion batteries will inevitably make people nervous.
From a scientific perspective, the reason for the explosion of lithium-ion batteries is usually that the uneven lithium deposition on the electrode surface leads to the growth of dendrites, which reduces the charge and discharge efficiency of the battery. There is even a short circuit inside the battery, causing battery failure or safety hazards. Scientists are all trying to find a solution. A few days ago, Chinese scholars proposed the use of a microspheres structure to capture lithium to limit lithium deposition and inhibit dendrite growth.
Dendrite growth is inhibited, so after more than 200 charge and discharge, the electrode can still maintain a high plating/stripping efficiency of 99%, which not only helps to extend The life of lithium-ion batteries can also effectively improve safety.
The above research comes from the research team of Guo Yuguo, a researcher at the Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences. The research has been published recently in the 'Nano Letters' of the Journal of the American Chemical Society (
The specific method proposed by Guo Yuguo’s team is to capture lithium through a microsphere structure. To limit its deposition and inhibit the growth of dendrites. The prepared microspheres are a composite material of carbon nanotubes and a porous silica protective layer. Experiments have proved that the composite material of this structure is very effective in controlling the behavior of lithium deposition. In addition. , The insulating coating can also prevent the concentrated flow of electrons and reduce the possibility of forming hot spots.
It is understood that Guo Shaojun’s research group can quickly exchange air by learning from the ant nest structure in nature. Features, designed an ionic gel electrolyte with a special functional group modified silica as the skeleton. This bionic ionic gel electrolyte has the ability to quickly transport lithium ions, and can spontaneously form particles on the surface of the metal lithium negative electrode. Collecting layers, thereby effectively inhibiting the growth of lithium dendrites. This achievement provides a new idea for the design of high-performance metal lithium-ion batteries using the bionic concept.
Previously, When solving the safety problem of lithium-ion batteries, many methods such as electrolyte additives, stable interfaces, and modified electrodes are used in the industry. Experiments have shown that the most efficient way to adjust lithium dendrite accumulation is to use the structure to adjust the battery. Things have been updated and updated a lot since they appeared. At present, lithium-ion batteries are generally used in mobile electronic devices. Compared with other types of batteries on the market, lithium-ion batteries can store more in the same unit. The energy is relatively stable. Even if it is not used, it does not discharge much, is light in weight, and has a long life. It combines many advantages, so it is widely used and can be seen in all walks of life. However, in conventional submarines However, lithium-ion batteries are not used on the above. Isn’t the advantage of lithium-ion batteries obvious, why not use it?
The main reasons for this are the following aspects: One is the cost. Although lithium-ion batteries can store more energy, the manufacturing cost of lithium-ion batteries with the same power is more than 4 times that of the lead-acid batteries currently assembled. According to the amount of tens of tons of submarines to be equipped, that is one A lot of money. There is also a long service life. Although the lithium-ion battery has a long life, it is based on the principle of full charge and full charge. It is naturally difficult for warships. It must be deployed according to the task. The battery life is not as good as other batteries. The most important point is safety, that is, lithium-ion batteries are easy to explode. This is because lithium-ion batteries will emit heat during charging and discharging, and will explode without guidance. Submarines are a kind of Confined space, if it is cooled by seawater, it is easy to be found by the enemy during war. Therefore, under the common use of these factors, the submarine does not use lithium-ion batteries, but lead-acid batteries.
< /p>
However, a new type of lithium-ion battery suitable for submarines is currently being developed. It is estimated that lithium-ion batteries will be seen on submarines soon.