质子电池负极材料W掺杂α-MoO3的制备和研究OA北大核心CSTPCD

Protons carry one positive charge with the smallest ionic radius and mass.Hydrogen is a ubiquitous element on earth,this makes rechargeable proton battery systems the next generation of energy storage batteries.To date,anode materials for proton batteries,such as WO3,TiO2,and MXenes,still suffer from low discharge capacity and poor rate performance.α-MoO3,one of the layered crystalline compounds composed of[MoO]6 octahedra double sublayers connected by van der Waals interaction.α-MoO3 possesses a high theoretical specific capacity of 558 mAh/g because of three electron reactions and low proton insertion potential,is recognized as one of the most promising anode materials for proton batteries.Unfortunately,α-MoO3 suffers severe lattice distortion and damage in aqueous electrolytes during the discharge process,causing rapid decay of the reversible capacity.In this study,we report the synthesis of W-doped α-MoO3 for the first time.The XRD and RAMAN results show that the substitution of Mo with W results in a stronger W—O bond and enhances the inlayer Mo=O bond.Additionally,the interlayer spacing of α-MoO3 increases from 13.84 to 13.87 Å after W-doping because the W6+has a larger radius(0.60 Å)than Mo6+(0.59 Å).Moreover,the CV results showed that the redox reactions of the W-doped material were mainly controlled by charge transfer between the electrode surface atoms rather than proton diffusion mass transfer.The reversible discharge capacities of the α-MoO3 and W0.035Mo0.965O3 were 202.4 and 189.2 mAh/g at 5 C(1 A/g),respectively.After 600 cycles,the capacity retention is 83.0% for W0.035Mo0.965O3 is higher than that of α-MoO3(69.6% ).Even at 125 C(25 A/g),W0.035Mo0.965O3 delivers a discharge capacity of 144.2 mAh/g which is higher than that of α-MoO3(90.7 mAh/g).Subsequently,the full Swagelok cell was assembled using MnO2 as the cathode,W0.035Mo0.965O3 as the anode,glass-fiber filter paper as the separator,and 2 mol/L H2SO4+1 mol/L MnSO4 as the electrolyte.At 15 C(3 A/g),the full cell exhibited a reversible capacity of 177.0 mAh/g and a capacity retention of 83.8% after 400 cycles.These results show that W doping effectively improves the cycling stability and rate performance of α-MoO3 materials.