LG Energy Solution Develops All-Solid-State Battery with Room-Temperature Charging

Charging Temperature Limit and Speed Improvement
Joint Research with University of California San Diego
Published in Latest Issue of Science
Securing Competitive Edge in Next-Generation Technology

LG Energy Solution Technology Research Institute

[Asia Economy Reporter Choi Dae-yeol] A domestic battery company has developed a technology that overcomes the limitations during the charging process, which has been pointed out as a weakness of all-solid-state batteries. All-solid-state batteries are attracting attention as next-generation batteries because they can increase energy density and enhance safety compared to the lithium-ion batteries currently in widespread use. As global technological competition intensifies with the goal of commercialization within a few years, this achievement is evaluated as having gained a favorable position.

LG Energy Solution announced on the 24th that a joint research paper detailing this technological development, conducted together with the University of California San Diego (UCSD), was published in the latest issue of the scientific journal Science (Vol. 373, No. 6562). According to the company, this joint research concerns technology that enables all-solid-state batteries to be charged rapidly at room temperature. Previously, charging was only possible at high temperatures above 60 degrees Celsius, but this technological limitation has been overcome. The company explained, "This is the first time that an all-solid-state battery using silicon has achieved a charge-discharge cycle life of over 500 cycles at room temperature."

All-solid-state batteries replace the liquid electrolyte between the battery’s cathode and anode with a solid electrolyte, which is expected to improve both efficiency and safety. Liquid electrolytes require safety devices to prevent accidents caused by expansion due to temperature changes or leakage from external shocks. In contrast, all-solid-state batteries are structurally stable and can increase energy density by filling the space originally occupied by safety devices and components with active materials that increase battery capacity.

This is why they are attracting attention as next-generation batteries and why development competition is fierce. However, existing all-solid-state batteries that use lithium metal as the anode to increase energy density are sensitive to temperature and could only be charged in high-temperature environments. Slow charging speed was also a limitation. To solve these problems, the LG and UCSD research teams removed conductive agents and binders from the battery anode and applied margin microsilicon anode material with particle sizes around 5 μm.

Charging process of the room-temperature operated long-life all-solid-state battery jointly developed by LG Energy Solution and UCSD

Silicon anode material has been considered a suitable material for increasing battery energy density because it has ten times the capacity of conventional graphite anode material, but it is known to be difficult to apply in practice due to large volume changes during charging and discharging. Previous studies applied nanosilicon with particle sizes below 100 nm (nanometers, one-tenth of a μm) to suppress volume changes of silicon anode material, but the microsilicon used in this study is cheaper and easier to use than nanosilicon. Furthermore, it maintained over 80% of its remaining capacity even after more than 500 charge-discharge cycles. According to the company, it is possible to increase energy density by about 40% compared to widely used lithium-ion batteries.

The results of this study are actual outcomes of the support project from the Battery Innovation Contest (BIC), which LG Energy Solution holds annually for open innovation. The company solicited technology proposals from universities and research institutions worldwide to encourage technological development in all areas related to battery life, safety, and cost.

Kim Myung-hwan, Chief Production and Purchasing Officer (CPO) of LG Energy Solution, said, "Through the research results with UCSD, we have taken a step closer to the commercialization of all-solid-state batteries, which are attracting attention as next-generation batteries," adding, "We will lead the global market with differentiated technology in the next-generation battery field as well."

This content was produced with the assistance of AI translation services.