With the rapid development of portable electronic devices and electric vehicles, people in addition to the pursuit of the large capacity of lithium-ion batteries and charging and discharging speed, more concerned about the safety of lithium-ion batteries. Repeatedly lithium-ion battery explosion incidents unavoidably make people nervous.
From a scientific level, is the usual cause of lithium battery explosion due uneven lithium electrode surface deposition "dendritic" (dendrites) growth, make the battery charge and discharge efficiency is reduced, and even appeared inside the battery short circuit, causing the battery failure or safety problems. Scientists are trying to find a solution. Recently, Chinese scholars put forward adopting a microsphere (microspheres) structure capture lithium, lithium to limit deposition and inhibit the growth of dendrite (dendritegrowth).
Due to the dendrite growth is restrained, so after more than 200 times charging and discharging, electrode can still keep high plating/stripping efficiency of 99%, this not only helps to prolong the life of lithium batteries, also can effectively improve security.
The study from the chemical research institute of Chinese academy of sciences molecular nano structure and nano technology key laboratory researcher yuguo guo's team. The study was recently in the journal of the American chemical society's "NanoLetters" .
Yuguo guo team put forward the specific method is that by microsphere structure (microsphere) to capture the lithium, to limit the sedimentary and inhibit the growth of dendrite. The preparation of porous silica microspheres as carbon nanotubes and protective layer of composite material, the experiments show that the structure of composite material is very effective to control lithium deposition behavior. In addition, insulation coating can prevent electron flow concentration and reduce the possibility of "hot spots".
It is understood that Guo Shaojun group nest structure by drawing from the nature to the characteristics of the rapid exchange of air, designed a kind of special functional group modified silica based gel electrolyte ions. The bionic ion gel electrolyte has the ability of fast transport lithium ion, and can spontaneously in lithium metal anode surface to form particle enrichment layer, effectively inhibit the growth of lithium dendrite. The results for the concept of using bionic design of high-performance metal lithium battery provides a new way of thinking.
Yuguo guo team thought that the study of lithium metal electrode design provides a new train of thought, can accelerate the practical application of lithium-ion batteries.
Previously, when solving safety problems of the lithium-ion batteries, the use of more is electrolyte additives, the stability of the interface and a variety of ways, such as modified electrodes. Experiments have proved that the structure adjustment of lithium dendrite accumulation is the most efficient way.
Peking University institute of technology Guo Shaojun group and Beijing institute of technology ren-jie Chen group together put forward by the "nest" structure solid electrolyte lithium dendrite inhibition method. The team's research papers in June 2017 in the international academic journals in “Energy & Environmental Science” officially published.