Don't look down on the plasticine! In the future, the safety of lithium battery may depend on it

The plasticine is the object that we are familiar with We can make all kinds of shapes with a little pinch When we throw it hard, it will harden quickly Cui Yi, a professor at Stanford University in the United States, has taken a fancy to the unique character of "soft or hard, which can be changed at will according to the force" As a protective coating of lithium metal battery electrode, it has significantly improved the cycle stability and safety of the battery Relevant research results were recently published in the Journal of the American Chemical Society (JACS), the top international journal of materials and chemistry Liu Kai, the first author of the paper and a postdoctoral student at the school of materials science and engineering at Stanford University, told reporters that the battery capacity depends on the type of electrode material Now the common lithium-ion battery on the market uses graphite as the negative material If it is replaced by lithium metal, its capacity can be increased tenfold However, the weakness of lithium metal battery, which is called "Holy Grail" of lithium battery, lies in that the micro shape of lithium metal will change dramatically in the process of charging and discharging, which will lead to the precipitation of lithium dendrites Lithium dendrite will not only reduce the capacity of the battery, but also cause short circuit in the battery, which may cause fire and explosion and other safety accidents The research results of Cui Yi's team show that applying a layer of plasticine with a thickness of only about 1 μ m on the surface of lithium metal can protect the lithium metal electrode almost perfectly In the normal charging and discharging process, lithium metal is deposited evenly on the electrode surface, and the force on the plasticine is very small The soft plasticine can adapt to the shape and volume change of lithium metal well, and it is firmly attached to the surface of lithium to protect the coating Once there are lithium dendrites "sticking out" in some areas, the plasticine coating will harden rapidly, thus effectively blocking the growth of lithium dendrites "Plasticine is like an intelligent coating, and its hardness can quickly give feedback as the lithium metal changes." Liu Kai said Cui Yi said the smart stimulus response coating proposed a new concept for lithium battery research and development.