James Tour of Rice University laboratory research members reveals the nanotubes film can effectively prevent the battery in the unprotected lithium metal anode in the natural growth of dendrite. As time goes on, the tentacles of the core and the branches can penetrate the battery electrolyte to the cathode, eventually lead to battery failure.
This problem is hampering the lithium metal application in the commercial market, but also encouraged the researchers around the world to solve this problem.
Lithium rechargeable faster than almost all electronic devices (including mobile phones and electric cars) in the lithium ion electrode is much faster, and its volume can hold energy is about 10 times of lithium ion electrode.
Professor Tour said: "in the lithium ion battery crystal growth to slow down the branch of one of the methods is to limit the battery charging speed. But in reality it is not like that. Instead they want charging speed can be faster."
He continued: "our research team in the journal advanced materials for the solution to this problem are described in detail, this method is very simple, and low cost, and is more effective in preventing the dendrite growth."
Professor our explained: "we do all the work is actually very simple, only need to give a lithium metal foil surface coated with a layer of multi-walled carbon nanotube film. Nanotubes film adhesion on the lithium metal surface, thin film will be changed from black to red, but if the film, in turn, can lead to the lithium ion diffusion.
Rice University researchers in 500 after the charge and discharge cycle, the morphology of lithium metal anode, as shown at left with a layer of carbon nanotube electrodes to prevent the dendrite growth. Right is no protection for lithium metal anode in the shape of the dendrite growth.
Rice University postdoctoral researcher Rodrigo Salvatierra said: "with the physical contact of metallic lithium on the nanotube film loss, but can be by adding lithium ion to keep its balance, and the lithium ion distribution on the nanotube film."
When using the battery, nanotubes film will be stored to discharge ion, while at the bottom of the lithium anode to recharge to maintain the capability of the film to prevent dendrite growth.
In previous experiments, we use sulfide carbon cathode, to more than 580 battery charge and discharge cycle test, found that the structure of the nanotube film can effectively quenches the dendrite growth. The researchers report, complete lithium batteries retain 99.8% of the coulomb efficiency, which is a measure of electronic in electrochemical system movement the basis of a good or bad.