Researchers from Wenzhou University, with colleagues from other universities in China and Argonne National Laboratory in the US, have engineered niobium tungsten oxide (NbWO) to accelerate the charging process in a Li-ion battery significantly.

In an open-access paper in Nature Communications, the team reports that engineered NbWO (rGO/NbWO) exhibits a capacity of 257 mAh g⁻¹ at 0.2 C and 116 mAh g⁻¹ at 80 C, which maintains a capacity of 92.7% for 500 cycles at a rate of 10 C. A LiFePO₄ pouch cell with the the rGO/NbWO anode cycled at 5 C and remained 96.1% at the first 100 cycles and 77.0% capacity after 500 cycles at a large rate of 5 C.

In this work, through direct visualization of Li⁺ electrochemically intercalated into micron-sized Nb₁₆W₅O₅₅, we discovered that the material’s fast charging capability is derived from a rate-dependent lattice relaxation process associated with the Jahn-Teller effect. We observed that the NbWO structure is highly sensitive to the rate: lithium ions tend to occupy lattice sites randomly at higher rates, alleviating the significant lattice distortions inherent in the NbWO structure, and facilitating the rapid intercalation of lithium ions.

Anomalously, at lower rates such as 0.1 C, lattice distortions became more pronounced, adversely affecting the structural stability. Moreover, [010]-preferred Li⁺ transport in Nb₁₆W₅O₅₅ crystals is verified to be the major bottleneck for fast charging, during which the entry of any desolvated Li⁺ into Nb₁₆W₅O₅₅ bulk through the prevailing non-(010) surfaces is deprived.

In light of these mechanistic insights, we propose the machine learning-assisted interface engineering strategy, which acts as a Li-attracting interface to collect the desolvated Li⁺ against re-solvation at the electrode/electrolyte interface and further transport them to the (010)-faceted entrance for swift Li⁺ intercalation, largely alleviating the anisotropy aftermath and enhancing the charging rate. Hence, it resulted in a significant improvement in high-rate performance (≈116 mAh g⁻¹ at 80 C, 45 s), far surpassing traditional Nb₁₆W₅O₅₅ (which exhibits a capacity below 50 mAh g⁻¹ at 60 C, 60 s), and meets the fast-charging criteria outlined by USABC (United States Advanced Battery Consortium defines fast charging as reaching 80% state of charge within 15 min (4 C rate), and our engineered NbWO achieves this even at nearly 40 C, 90 s). The results obtained from this investigation will contribute to the knowledge of lithium storage mechanisms in fast-charging materials, contributing to the development of advanced fast-charging batteries.

—Guyo et al.

Resources

• Guo, Y., Guo, C., Li, P. et al. Improving the fast-charging capability of NbWO-based Li-ion batteries. Nat Commun 16, 2441 (2025). doi: 10.1038/s41467-025-57576-1