Tunable Surface Charge Redistribution via Lattice Strain Engineering in B/Mo Co‐Doped NiV ₂ O ₆ for High‐Power Supercapacitors

Abstract The pursuit of high‐energy‐density supercapacitors remains challenged by the irreversible surface charge accumulation and sluggish ion dynamics in conventional vanadate cathodes. To address these limitations, a lattice strain engineering strategy is devised through B/Mo co‐doping in NiV ₂ O ₆ , which enables dynamic regulation of surface charge distribution via atomic‐level stress manipulation. Density functional theory (DFT) calculations demonstrate that high‐valence Mo ⁶⁺ induces compressive lattice strain (–4.4%) to strengthen metal‐oxygen covalency, while low‐electronegativity B ³⁺ generates tensile strain (+ 2.9%) that enhances surface hydroxyl affinity. This strain dichotomy optimizes OH ⁻ adsorption energetics by 0.28 eV and creates gradient oxygen vacancy. The cooperative dopant effects significantly enhance charge‐transfer kinetics, endowing the B/Mo‐NiV ₂ O ₆ /NF electrode with a superior specific capacitance of 2850 F g ⁻¹ (1 140 C g ⁻¹ ) at 1 A g ⁻¹ . In situ Raman reveals reversible oxygen vacancy migration along (004) crystallographic planes during cycling, which dynamically dissipates structural stress. A solid‐state asymmetric supercapacitor delivers a 1.8 V operational window with remarkable energy/power density (38.35 Wh kg ⁻¹ /900 W kg ⁻¹ ) and 75% capacity retention after 10 000 cycles. Practical viability is demonstrated by powering 20 parallel‐connected light‐emitting diodes (LEDs). This work pioneers a lattice strain‐mediated surface charge regulation paradigm for durable high‐power energy storage.