Abstract
Although pseudocapacitive manganese dioxide(MnO2)integrates the high-power merit of carbonaceous materials with the high-energy merit of battery-type materials,it still has a long way to go in achieving a more satisfactory balance of higher energy and power density,and in decoupling the relationship of structural character-istics with energy storage performance.To realize such goals,a bottom-up[WO6]-perturbed[MnO6]assembly strategy has been developed here due to their similar structure,yet mismatched lattice parameters.This facile protocol is capable of finely controlling the morphology and crystal structure of MnO2 by adjusting its internal[WO6]concentration.Therefore,the as-prepared Wx-MnO2 is treated as an ideal platform to scrutinize the correlations of the structure with the energy storage per-formance.The operando Raman spectra and finite element analysis have fully demonstrated the superiority of the locally ordered defects-enriched structure of W0.02-MnO2,which could reach a favorable balance between the ion diffusion equilibrium time and the number of active sites.As a result,the W0.02-MnO2 is able to deliver a high capacitance of 292 F·g-1 at a current density of 1 A·g-1 and a remarkable rate performance with a 60％ capacity retention at a current density of 50 A·g-1.The further unveiled structure-performance relationship provides a guideline for the design of better pseudocapacitive energy storage devices.
基金项目
National Natural Science Foundation of China(22105164)
National Natural Science Foundation of China(21875205)
National Natural Science Foundation of Hebei Province(B2022203009)
Hebei Province Foundation for the National Natural Science Foundation(206Z4404G)
subsidy for Hebei Key Laboratory of Applied Chemistry after Operation Performance(22567616H)
NETL
NSTL
万方数据