China energy storage net news: the Chinese American scientists said 6, they developed a new based on aqueous electrolyte of lithium ion batteries, not only eliminate the risk of conventional lithium ion battery explosion, and the energy density up to the level of the traditional lithium-ion batteries, lithium ion battery safety practical direction taken a big step.
The work, according to xinhua news agency on September 7, from the university of Maryland, Yang Yin, Ph.D., professor wang and the U.S. army research laboratory in collaboration with senior chemist Xu Kang, were published in the United States in the journal of joule cell press group.
"This is the first 4-volt battery for the water-based electrolyte, which is a fundamental breakthrough in principle."Mr. Yang said in an email to reporters.They explain that the traditional commercial lithium ion battery USES highly flammable organic electrolyte, which is a serious safety hazard.With non combustible organic electrolyte aqueous electrolyte replacement of the problem is that the former generally less than 2 volts, electrochemical stability window once the electrode voltage is more than the number, the electrolyte loses stability, so the energy density is limited.
The key to the new study, they explained, was to avoid lithium metal or graphite electrodes in direct contact with water molecules in water-based electrolytes and lead to hydrogen production.To this end, they developed a very hydrophobic colloidal material, coated in the electrode surface, effectively preventing the failure of the electrode caused by water decomposition side reaction.
Crucially, they found that in the first charge and discharge loop, protective layer on the in situ formation on the surface of the cathode is more specific component in the solid electrolyte interface layer of dense hydrophobic, further passivation of the cathode surface, and a solid interface layer that can be in local repair damaged case, to ensure the long-term stability of the battery.
Wang chunsheng and xu kang and others pointed out that the research results provide new directions and ideas for the development of safe water-based lithium ion batteries in high-voltage Windows.In the basic scientific sense, "stable 4-volt aqueous electrolyte can bring many new opportunities to various electrochemical devices".At the same time, the water-based lithium ion battery can eliminate the necessary safety devices in the traditional lithium-ion batteries, further reducing the weight of the battery components.
They stress that the current research is only a laboratory test of the concept, and that it is a long way from commercialization.Next, they plan to further optimize and improve the electrolyte layer material chemical composition and cell structure, and improve the battery cycle life, from 70 to now more than 100 to 500 cycles of commercial standards.