New battery design boosts capacity by 167%, easing EV range anxiety

Professor Yu-Sheng Winston Su (center) amd his Battery | Energy | Semiconductor Technology (BEST) Lab team

Researchers at National Yang Ming Chiao Tung University have developed a novel battery design that increases capacity by 167%, offering a potential breakthrough in addressing electric vehicle (EV) range anxiety and advancing energy storage technology.

Led by Professor Yu-Sheng Winston Su from the university’s International College of Semiconductor Technology, the research team reimagined the conventional design of lithium-ion batteries by focusing on lithium titanate (Li₄Ti₅O₁₂, or LTO), a material long regarded as one of the safest anode options.

LTO is known for its exceptional structural stability, as it undergoes almost no volume expansion during charging and discharging. This property gives it a long cycle life and strong thermal stability, making it suitable for applications requiring fast charging, such as electric transportation and large-scale energy storage systems. However, its relatively low energy density has limited its adoption in EV markets.

Challenging traditional assumptions, the team found that lithium ions are not strictly necessary in the electrolyte for LTO-based batteries to function. Their study demonstrated that LTO can operate effectively even when paired with a sodium-ion electrolyte. Under certain conditions, the battery showed improved capacity, cycle life, and rate performance compared to conventional lithium-ion systems.

In the new design, lithium metal remains the primary energy carrier, while sodium ions play a supporting role. A small number of sodium ions enter the LTO crystal structure, causing slight and reversible lattice expansion. This process effectively creates additional space within the material, allowing lithium ions to move more freely in and out, thereby enhancing overall battery capacity without compromising stability.

The findings, published in the journal Small Structures, could have significant implications for the EV and energy industries. In addition to improved safety and longevity, the enhanced capacity positions LTO-based batteries as a promising candidate for high-power, fast-charging applications.

Moreover, sodium is more abundant and cost-stable than lithium. Replacing part of the electrolyte with sodium-based salts could reduce costs and strengthen supply chain resilience for large-scale battery and energy storage systems, the researchers said.