Elevated temperatures cause all-solid-state batteries to degrade

All-solid-state batteries (ASSBs) are next generation battery systems that may replace organic-based electrolytes with inorganic, solid electrolytes. Because they employ non-flammable material, the batteries offer safety advantages for use in electric vehicles. The solid nature of the components also increases design flexibility compared to conventional lithium-ion batteries, which must safely contain the liquid electrolyte.

To mount the batteries in electric vehicles, ASSB performance needs to be evaluated under various practical operating conditions. Yoon et al. exposed a representative ASSB system to various storage temperature variations at various states of charges, then measured and characterized its electrochemical properties.

“One of the important conditions was to store and idle the charged-state ASSBs in three different storage conditions (-20, 20 and 70 degrees Celsius) for about a week,” said author Kisuk Kang. “It is like a scenario where an electric car, with battery capacity remaining, is parked on cold or hot days for about a week, just like during your holidays or a business trip.”

The team found storage as low as 70 degrees Celsius can induce decomposition when the electrolyte is in contact with oxide cathode materials. That degradation creates a nonideal, porous cathode-electrolyte interface, leading to large interfacial resistance and a dramatic reduction in battery performance.

“Our findings educate that the stability of the cathode-electrolyte interface needs to be carefully investigated at various practical operational conditions for actual applications in ASSBs,” said Kang. “We are planning to examine chemical/electrochemical stability of various other solid electrolytes in contact with oxide cathode materials and propose a strategy to mitigate this unexpected degradation.”

Source: “Detrimental effect of high-temperature storage on sulfide-based all-solid-state batteries,” by Kyungho Yoon, Hwiho Kim, Sangwook Han, Ting-shan Chan, Kun-Hee Ko, Sugeun Jo, Jooha Park, Sewon Kim, Sunyoung Lee, Joohyeon Noh, Wonju Kim, Jongwoo Lim, and Kisuk Kang, Applied Physics Reviews (2022). The article can be accessed at https://doi.org/10.1063/5.0088838 .

This paper is part of the Energy Storage and Conversion Collection, learn more here .