Claims of a ‘game changer’ in solid-state battery chemistry

SK On Company Ltd, the EV battery manufacturing unit of South Korea’s energy and chemicals conglomerate SK Group, says it has developed a new solid-state electrolyte material which significantly improves the performance of electric vehicle (EV) batteries.

The new material is described as a “game changer” in peer-reviewed scientific journal Advanced Functional Materials and could significantly increase the company’s competitiveness in the solid-state battery sector. The new solid electrolyte material, developed in collaboration with Dankook University in South Korea, is said to improve lithium-ion conductivity by 70% compared with existing materials and improves battery capacity by 25%.

SK On said the improvement has been achieved by adjusting the additives of lithium lanthanum zirconium oxide (LLZO), a material being developed for use in lithium-based solid-state battery electrolytes, adding that “its atmospheric stability has been improved by tailoring the microstructure of LLZO – which often loses conductivity when exposed to air”. Lithium-ion conductivity is a key factor in a battery’s power output and charging speed.

Choi Kyoung Hwan, executive vice president at SK On’s next-generation battery research and development centre, told the journal: “The solid electrolyte with improved ion conductivity and atmospheric stability is expected to have a significant ripple effect, as it is an innovative technology for high-quality all-solid-state batteries”.

SK On and Dankook have applied for patents for the technology in South Korea and overseas.

SK On said the new solid electrolyte may be used in current nickel-cobalt-manganese (NCM) solid-state battery cathodes as well as in next-generation batteries such as lithium-sulphur batteries and lithium-air cells.

Solid-state batteries are seen as the future of EV batteries, with leading global battery manufacturers planning to begin mass production in the second half of the decade. They are said to offer higher energy-density and improved safety compared with existing EV batteries.

SK On is scheduled to complete construction of a pilot plant for solid-state batteries in 2024 and aims to produce prototypes by 2026 and start mass production in 2028.