Researchers at Seoul National University of Science and Technology have developed an off-stoichiometric lithium titanium phosphate anode material designed to improve the fast-charging performance and safety of lithium-ion batteries.
The development could be particularly relevant to EVs, where higher charging rates can reduce charging time but also increase stress at the anode-electrolyte interface. Under these conditions, lithium plating can accelerate battery degradation and create additional safety concerns.
“We have developed an off-stoichiometric anode composition based on the NASICON-structured lithium titanium phosphate, renowned for its exceptional structural and thermal stability,” said Associate Professor Dongwook Han, who led the research team. “This design induces spontaneous phase transformations at the subsurface of active material particles, overcoming kinetic limitations and thus enabling stable, fast-charging.”
The researchers modified lithium titanium phosphate by increasing its phosphorus-to-titanium ratio. The resulting titanium deficiency produces titanium phosphate-rich regions near the surface of the active material particles.
Off-stoichiometric lithium titanium phosphate anodes demonstrated high-rate capability and cycling stability while remaining compatible with high-voltage cathodes. (Image: Associate Professor Dongwook Han from Seoul National University of Science and Technology, Korea)
According to the researchers, these regions lower the energy barrier for lithium ions crossing the anode-electrolyte interface and create faster ion-transport pathways near the particle surface. The structure also accommodates volume changes during high-rate charging, helping protect the underlying NASICON structure from irreversible damage.
In rate capability testing, the off-stoichiometric lithium titanium phosphate/carbon, or OS-LTP/C, composite retained 86% of its initial capacity at a 10C charging rate. The material also demonstrated cycling stability for more than 250 cycles. Full-cell testing showed similar high-rate performance when the anode was paired with high-voltage cathode materials.
For EV battery developers, the results point to a potential materials-based approach for increasing charging rates without relying solely on changes to charging infrastructure or thermal management. Improving ion transport at the anode could help address one of the limitations that currently constrains how quickly lithium-ion EV batteries can be charged.
“Our approach represents a new paradigm for designing fast-charging batteries and is broadly applicable for a wide range of future energy storage systems, including all-solid-state batteries,” Han said. “This strategy could help make electric vehicles more practical by reducing charging times while improving safety and supporting renewable energy grids.”
Reference
“Unlocking Ultrafast Charging: Synergizing Embedded Pseudocapacitive Domains and Flexible Lattice Dynamics in Off-Stoichiometric LiTi₂(PO₄)₃ Anodes,” Advanced Functional Materials, June 1, 2026. DOI: doi.org/10.1002/adfm.76250
Filed Under: Batteries, Technology News