Study On Electrochemical Hydrogen Storage Performance Of Cobalt-phosphorus Composite

Co-based alloy has excellent electrochemical hydrogen storage performance.as a negative electrode material of Ni-MH battery,it has received extensive attention in the field of new energy.This thesis takes Co-P alloy as the research object,doped with flower-like Ni/C nanocrystals,MWCNT/MoS₂ composite material and C@Ni S core-shell material to form a composite material dominated by Co-P alloy.The microscopic morphology and electrochemical properties of Co-P composite materials are studied,and the details are as follows:（1）The flower-like Ni/C nanocrystals were prepared by solvothermal method,the Ni/C nanocrystals and the Co-P alloy are compounded by ball milling to form a Co-P+Ni/C composite material.The maximum discharge capacity of the Co-P+Ni/C composite is 635.8m Ah/g,and the capacity retention rate is 66.3%.Studies have shown that the unique lamellar structure and electrocatalysis of flower-shaped Ni/C nanocrystals can effectively improve the electrochemical hydrogen storage performance of Co-P alloys.（2）The MoS₂ and multi-walled carbon nanotubes（MWCNT）are combined by solvothermal method,and then the Co-P+MWCNT/MoS₂ composite material was prepared by the high-energy ball milling method.The composite material shows better electrochemical performance than Co-P alloy.At a current density of 30 m A/g,the maximum discharge capacity can reach 702.9 m Ah/g,and after 50 cycles,the discharge capacity can still be maintained at 478.7 m Ah/g.Studies have shown that the excellent conductivity and hollow tubular structure of MWCNT can accelerate charge transfer and provide hydrogen transport channels.MoS₂ can inhibit the dissolution and oxidation of active substances.After the two form a composite material,the synergistic effect of MWCNT and MoS₂ further improves electrochemical hydrogen storage performance of Co-P alloy.（3）A core-shell material was prepared using a low-temperature water bath method,the core-shell material is formed by Ni S coated porous carbon（C@Ni S）,and the composite material of Co-P alloy and C@Ni S was prepared by ball milling.When the molar ratio of Ni S to porous carbon is 4,the electrochemical performance of the composite is the best,the maximum discharge capacity can reach 697.8 m Ah/g,and the capacity retention rate is69.2%.Studies have shown that when the catalytic Ni S nanosheets are evenly coated on the porous carbon surface,they can provide more active sites for electrochemical reactions,accelerate the charge transfer rate between the electrode and the electrolyte,and promote the diffusion of hydrogen,Thereby improving the electrochemical hydrogen storage performance of the composite material.