Electric-vehicle drivers may soon have a new reason to stop fearing long charging times. Researchers in South Korea have developed a redesigned lithium-ion battery anode that retained 86% of its initial capacity even when charged at an extremely demanding rate of 10C, a performance level associated with ultra-fast charging. The material also maintained stable operation for more than 250 cycles and worked with high-voltage cathodes, suggesting that the approach could help overcome one of the most persistent barriers to faster, safer rechargeable batteries.
Fast charging has always forced lithium-ion batteries into an uncomfortable trade-off. Increasing the charging current can dramatically shorten charging times, but it also accelerates chemical and structural damage inside the cell. At the anode, lithium ions may not be absorbed quickly enough into the host material. Instead, metallic lithium can deposit on the surface, creating irregular structures that increase the risk of internal short circuits, capacity loss and, in extreme cases, thermal runaway. Repeated rapid charging can also destabilize the solid-electrolyte interphase, a thin layer that forms where the electrode meets the electrolyte and controls how ions and electrons move across the interface.
The research team, led by Associate Professor Dongwook Han of Seoul National University of Science and Technology, focused on lithium titanium phosphate, or LTP. This compound has a NASICON-type crystal structure, a framework known for its thermal and structural stability and for providing channels through which lithium ions can move. LTP operates at a relatively high potential compared with conventional graphite anodes, reducing the likelihood of lithium plating during charging. However, its practical performance has been limited by sluggish interfacial kinetics and insufficient conductivity, problems that become especially serious when the battery is pushed to high charging rates.
Rather than using a perfectly balanced chemical composition, the researchers deliberately shifted the ratio of phosphorus to titanium. This “off-stoichiometric” design created a titanium-deficient version of the material. In the resulting anode, titanium phosphate, or TPO, domains formed near the surfaces of LTP particles. These nanoscale or near-surface regions changed how lithium ions interacted with the electrode, effectively creating kinetic gateways at the anode–electrolyte interface.
The significance of the strategy lies in how these altered domains manage the movement of lithium ions. During charging, ions must leave the electrolyte, cross the interface and enter the active particles. Each stage presents an energy barrier, and the interface can become a bottleneck when current is high. According to the researchers, the TPO-rich regions reduce this barrier and provide faster pathways close to the particle surface. The result is a more efficient transfer of lithium ions into the electrode, helping to prevent the accumulation of lithium at the surface that can trigger harmful plating.
The modified structure also appears to improve the anode’s ability to withstand repeated expansion and contraction. The TPO framework contains relatively unconstrained phosphorus–oxygen–phosphorus linkages, which provide additional flexibility within the surrounding structure. These bonds can accommodate the volume changes associated with lithium insertion and removal, reducing the mechanical stress that often leads to cracking, phase degradation or loss of electrical contact. At the same time, the underlying NASICON framework remains sufficiently robust to resist irreversible structural collapse during rapid cycling.
In tests, the off-stoichiometric LTP combined with carbon, known as OS-LTP/C, preserved 86% of its initial capacity at a 10C charging rate. In practical terms, a 10C rate corresponds to charging at a current that could theoretically fill a battery in roughly one-tenth of an hour, although real-world charging time depends on the complete cell design and operating conditions. The pristine LTP/carbon comparison electrode showed a sharp decline in capacity under the same demanding conditions. The redesigned composite also delivered stable cycling for more than 250 cycles, indicating that its fast-charge behavior was not achieved simply by sacrificing durability.
The researchers further tested the material in full cells rather than relying only on simplified laboratory half-cell configurations. These full-cell demonstrations showed similarly strong rate performance and compatibility with high-voltage cathodes. That result is important because anode materials must operate as part of a balanced electrochemical system; a promising electrode can lose its value if it cannot be paired with cathodes that deliver high energy density. Compatibility with higher-voltage cathodes could therefore broaden the range of battery architectures in which the off-stoichiometric LTP strategy may be used.
The work points to a broader design principle for energy-storage materials: performance may be improved not only by discovering entirely new compounds, but also by intentionally introducing controlled chemical imbalance into familiar structures. By engineering the composition near the particle surface, the researchers created a material that combines rapid ion transport, structural flexibility and thermal robustness. Han says the concept could be extended to other rechargeable-battery systems, including all-solid-state batteries, where contact resistance and interfacial ion transport are major technical challenges. Although further testing will be required to evaluate large-format cells, long-term operation and manufacturing scalability, the results offer a promising route toward batteries that charge faster without compromising safety and service life.
Subject of Research: Lithium-ion battery anodes and fast-charging energy-storage materials
Article Title: Unlocking Ultrafast Charging: Synergizing Embedded Pseudocapacitive Domains and Flexible Lattice Dynamics in Off-Stoichiometric LiTi2(PO4)3 Anodes
News Publication Date: 1 June 2026
Web References: https://doi.org/10.1002/adfm.76250
References: Advanced Functional Materials, “Unlocking Ultrafast Charging: Synergizing Embedded Pseudocapacitive Domains and Flexible Lattice Dynamics in Off-Stoichiometric LiTi2(PO4)3 Anodes,” DOI: 10.1002/adfm.76250
Image Credits: Associate Professor Dongwook Han, Seoul National University of Science and Technology, South Korea
Keywords
Fast-charging batteries, lithium-ion batteries, lithium titanium phosphate, LTP anodes, off-stoichiometric materials, NASICON structure, battery safety, electric vehicles, energy storage, materials science
Tags: advanced battery materials researchhigh-capacity anode designhigh-voltage cathode compatibilitylithium-ion battery safety improvementsovercoming fast-charging limitationspreventing thermal runaway in batteriesrapid charging technologySeoul researchers innovative battery solutionsstable battery cycle performancestructural stability during rapid chargesustainable electric vehicle energy storageUltra-fast-charging lithium-ion batteries
