Tunable Surface Charge Redistribution via Lattice Strain Engineering in B/Mo Co‐Doped NiV <sub>2</sub> O <sub>6</sub> for High‐Power Supercapacitors
Yanfei Pang, Lili Wu, Jianjun Liu, Disheng Tang, Fei Xu, Mingsheng Cen, Zehua Wang, Yulu Xie, Hao Yang, Muhammad‐Sadeeq Balogun, Yuwen Hu
Abstract
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.