In the wake of the explosion of Samsung Note 7 mobile phone and a number of mobile phones catching fire in recent years, lithium-ion battery safety has become a major issue for the mobile-phone industry. A breakthrough was achieved recently, as a joint R&D team of Drexel University of the U.S., Tsinghua University, and Huazhong University of Science and Technology of China discovered that the addition of some nanodiamonds to electrolytic solution can help stabilize lithium-ion battery, a core component for mobile phones, NB PCs, and electric cars.
The addition of nanodiamond, found the R&D team, can dampen the formation of dendrite, a major cause for short circuit of battery.
Similar to common battery, lithium-ion battery consists of anode, cathode, and electrolytic solution, with lithium ion shuttling between anode and cathode, discharging power. A major cause for short circuit is the formation of dendrite. After multiple discharging and charging, solid-electrolyte interphase (SEI) is likely to form between anode/cathode and electrolytic solution and may touch cathode, after increase of its length, causing short circuit, which may ignite electrolytic solution, often flammable. To solve the problem, some scientists have substituted graphite for metal as the material for anode but the former has lower efficiency than the latter.
Gogotsi, a researcher at Drexel University, points out that the study aims to solve or reduce short circuit of lithium-ion battery.
Researchers found that addition of nanodiamond to electrolytic solution can dampen formation of dendrite. "It's like playing Tetris. After stacking the cubes randomly, the game is over. You can reposition the cubes to lengthen the game. Likewise, addition of nanodiamond can slow down formation of dendrite," explains Gogotsi.
Gogotsi admits that with the study still in an initial stage, the method can lengthen the stability period for battery discharging/charging to 200 hours, which is fitted for some industrial usages but is insufficient for application in smartphones or NB PCs. In the next step, researchers will test the result in different physical environments and temperatures. "Though unlikely to root out dendrite, the technology is certain to greatly boost the potential of the battery industry," remarks Gogotsi.
(Cooperative media: TechNews, photo courtesy of Drexel University)