Tokyo Institute Of Technology Develops A New All-solid Battery With Low Resistance

- Oct 09, 2019-

Recently, the research team at Tokyo Institute of Technology in Japan has solved a major defect in all-solid-state batteries by developing a low-resistance battery at the interface between the electrode and the solid electrolyte. The new battery exhibits excellent electrochemical performance, significantly exceeding traditional lithium (Li) ion batteries, demonstrating the promise of all-solid-state battery technology and the potential to change portable electronics. The research results are currently published in the journal ACSAppliedMaterials&Interfaces.

Currently, rechargeable lithium ion batteries have been widely used in various electronic devices. However, scientists and engineers believe that traditional lithium-ion battery technology has been developed completely, so new batteries need to be developed.

All solid-state batteries use solid, non-liquid electrolytes and are a new type of lithium-ion battery that has proven to be a safer and more stable energy storage device with higher energy density. However, the use of such batteries is currently limited by the fact that the resistance at the electrode/solid electrolyte interface is too high, which severely hinders rapid charge and discharge.

The research team of Tokyo Institute of Technology and Tohoku University in Japan, led by TaroHitosugi, used Li(Ni0.5Mn1.5)O4 (LNMO) as an electrode material to develop an all-solid-state battery with extremely low interface resistance. By preparing under ultra-high vacuum conditions, it is possible to ensure that there is no impurity at the electrolyte/electrode interface.

The crystal structure of the thin film of the battery was analyzed by X-ray diffraction and Raman spectroscopy. It was found that Li ions spontaneously migrated from the Li3PO4 solid electrolyte layer to the LNMO layer, and half of the LNMO was converted to L2NMO at the Li3PO4/LNMO interface. Then during the charging process, reverse reversible migration occurs to regenerate the LNMO.

The electrical resistance spectroscopy characterizes the electrical resistance of the interface to be 7.6 Ω cm-2, which is two orders of magnitude smaller than the previously reported LMNO-based all-solid-state battery, and even smaller than the resistance of liquid electrolyte based lithium-ion batteries. The all-solid-state battery is capable of rapid charge and discharge, and in addition, the cycle characteristics of the battery are good, and no performance degradation occurs after 100 charge/discharge cycles.

Li(Ni0.5Mn1.5)O4 is a promising material that provides higher voltages and increases the energy density of lithium-ion batteries. The research team hopes that the research will promote the development of high-performance all-solid-state batteries, thus revolutionizing portable electronic devices and electric vehicles.