The high operational capability of fast-charging lithium-ion batteries (LIBs) at low temperatures (<−30°C) is essential for frequency regulation and peak-load shifting of power grids in cold regions. However, the low-temperature performance is seriously plagued by the sluggish Li⁺ diffusion and high-voltage polarization. Herein, the heterostructure-induced built-in electric field is constructed by selected nitriding of TiNb₂O₇, which demonstrates high accessibility for accelerated low-temperature dynamics. The introduced charged phase-junction interface enables promoted Li⁺ diffusion rates, enhanced Li⁺ adsorption, and reduced lattice strains. The mosaic TiNb₂O₇/TiNbN₂ heterostructure displays an outstanding specific capacity of 241.5 mA h g⁻¹ at −30°C, corresponding to 89% retention compared with that at 25°C. It even delivers a high-capacity retention of 96% at a 5C rate after approximately 1,000 cycles at −30°C. Our work provides new insight into structure-function relationships for developing fast-charging batteries for cold-region accumulation of electric energy.

快充锂离子电池（LIB）在低温（<-30°C）下的高运行能力对于寒冷地区电网的调频和调峰至关重要。然而，低温性能受到Li ⁺扩散缓慢和高压极化的严重困扰。在此，异质结构诱导的内建电场由 TiNb ₂ O ₇的选择性氮化构成，这证明了加速低温动力学的高可及性。引入的带电相结界面可提高 Li ⁺扩散速率、增强 Li ⁺吸附并降低晶格应变。镶嵌TiNb ₂ O ₇/TiNbN _{2异质结构在-30°C 时显示出 241.5 mA hg} ^-1的出色比容量，与 25°C 时相比保留了 89%。在 −30°C 下大约 1,000 次循环后，它甚至可以在 5C 倍率下提供 96% 的高容量保留。我们的工作为开发用于寒冷地区电能积累的快速充电电池的结构-功能关系提供了新的见解。