'Just 20 minutes to charge': Researchers develop silicon battery material enabling 1,000 km range

"Pushing past the limits of electric vehicle batteries."

Researchers have developed a key battery material that could allow an electric vehicle to travel between Seoul and Busan — and back — on a single charge completed in just 20 minutes.

A research team led by Park Su-jin, a chemistry professor at POSTECH (Pohang University of Science and Technology), and researcher Je Min-jun, working alongside a team led by Choi Jang-wook, a professor in the School of Chemical and Biological Engineering at Seoul National University, and LG Energy Solution, has succeeded in developing a "high-strength silicon material" for rechargeable batteries that resists fracturing even after repeated charge and discharge cycles.

The battery remains the central challenge for electric vehicles, with driving range and fast-charging capability determining their competitiveness. Graphite has long been the dominant anode material in EV batteries, but its energy storage capacity has already reached its theoretical ceiling. Silicon emerged as a candidate to overcome that limitation.

Despite storing up to 10 times more energy than graphite, silicon has been held back from commercial use by severe particle fracturing caused by extreme volume expansion during charging and discharging.

While previous research managed to improve either driving range or charging speed — but not both — this study achieved both simultaneously, making it a significant advance.

The team precisely embedded lithium fluoride (LiF) crystals measuring 32 nanometers inside silicon oxide particles. The approach draws on the Hall–Petch relationship — which holds that strength increases as crystal size decreases, up to a point — and the inverse Hall–Petch effect, which describes how strength drops when crystals become too small. The team also applied a specialized coating to the particle surface that allows ions to pass through readily while enabling rapid electron movement, achieving fast-charging performance alongside structural durability.

In testing, the material held volume expansion to just 18.9 percent during charge and discharge cycles — a stark contrast to the roughly 300 percent expansion seen in conventional silicon, in effect rendering it impervious to the problem. The material also operated stably for more than 1,000 cycles under rapid-charging conditions — from 10 to 80 percent charge in 20 minutes — and sustained normal operation for more than 500 cycles in a 1.26 Ah pouch-type battery. Energy density reached 402 watt-hours per kilogram and 1,125 watt-hours per liter, well above the levels found in electric vehicles currently on the market.

The research team said that if the technology is applied to actual electric vehicles, it could contribute to developing an EV capable of traveling approximately 1,000 kilometers on a single charge.

"We resolved the fracturing problem in silicon anodes by simultaneously increasing both strength and Young's modulus," Park said. "This will help accelerate the commercialization of next-generation batteries that satisfy both high energy density and fast-charging requirements." The findings were recently published online in Nature Communications.