| Sodium ion battery is considered as a potential energy storage battery due to its wide distribution of sodium resources,low cost and excellent safety performance.It is the key to make a progress of sodium ion battery to research and develop a new type of practical and high-performance anode material for large-scale energy storage.Antimony based alloy anode material is gradually considered as a promising anode material for sodium ion battery because of the advantages of simple synthesis method and high specific capacity,However,in the process of sodium storage,the alloy formed between antimony and sodium results in large volume change,which hinders its practical application in sodium ion batteries.In this paper,I have make a design and construction of nanostructured antimony based alloy anode materials,combined with porous carbon composite strategy,to inhibit the volume change of antimony and improve the performance of sodium storage,the research contents are as follows:Firstly,3D porous Sb-Co nanocomposites were synthesized by a simple reduction precipitation method and used as anode materials for sodium ion batteries.As an anode for SIBs,the Sb-Co nano-composites deliver a reversible capacity of 717.6 m A h g-1at 60 m A g-1and a 377.8 m A h g-1reversible capacity at 6000 m A g-1.Enhanced electrochemical performance of porous Sb-Co nanocomposites can be attributed to the synergistic effect of the Sb nanoparticles,3D porous nanostructure and the incorporation of Co element.Secondly,Ni Sb@PEO nanocomposites with hollow structure were successfully synthesized by solvothermal method.Compared with hollow nanospheres of Ni Sb,it is found that Ni Sb@PEO have higher capacity,better cycle and rate performance used as anode materials for sodium ion batteries.The initial charging capacity of Ni Sb@PEO is430 m A h g-1at 100 m A g-1.After 50 cycles,the charging capacity is still at 390 m A h g-1,and the coulomb efficiency is basically over 95%,it still have a charging capacity of 284m A h g-1at 1600 m A g-1.When the current density drops to 50 m A g-1,the charging capacity can be restored to 390 m A h g-1.These results demonstrate that the Ni Sb@PEO are promising anode materials for SIBs.Finally,Fe Sb/N-C nanocomposites were synthesized by two steps of freeze-drying and low-temperature sintering with Na-Cl as template and ammonium citrate as carbon and nitrogen sources,SEM and TEM images show that the Fe Sb alloy particles with a diameter of 20 nm are firmly anchored on the nitrogen doped porous carbon network.As an anode for SIBs,the Fe Sb/N-C nanocomposites deliver a reversible charging capacity of330,300,265,236,210 and 187 m A h g-1at the current density of 100,200,400,800,1600 and3200 m A g-1,When the current density returns to 100 m A g-1,the charging capacity returns to 296 m A h g-1,and the coulomb efficiency remains above 98%.Under the current density of 1100 m A g-1?2.5 C?,the charging capacity of the material can still be maintained at 221m A h g-1after 1000 cycles,and the coulomb efficiency is always close to 100%,Enhanced electrochemical performance of Fe Sb/N-C nanocomposites can be attributed to the synergistic effect of the N-doped carbon nano network structure and Fe Sb nanoparticles,it can keep the structural stability of the composite,and avoid the direct exposure of Fe sb nanoparticles in the electrolyte.At the same time,this structure can effectively shorten the transport path of sodium-ions,enhance the transport rate of charged particles,and improve the overall conductivity of the material. |
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