The Influence Of Battery Additives On The Performance Of Anode In Iron-Nickel Battery

In the face of today new energy electric vehicles and power equipment market demand, in viwe of the fact that iron nickel battery has the advantages of high theoretical capacity, green environmental protection, long cycle life, safe, high abuse and resistant performance etc., in recent years, Enterprise and University researchers pay more attention to iron nickel battery. However, for the iron electrode, there still exist the problems such as the passivation of the electrode and the serious hydrogen evolution. In this paper, we study from the following four aspects: including the preparation methods of the materials, electrode additives, electrolyte additives, optimize the electrode performance. And some meaningful research results have been obtained.Nano-Fe₃O₄ materials were prepared by precipitation oxidation method. It obtained the size of 20 nm samples which have high purity and excellent electrochemical activity. Its initial discharge capacity of the electrode was up to 250 m Ah/g at 0.1 C.It is found that the electrochemical performance of the electrodes doped with Ni S is better when three kinds of sulfide additives（Fe S、Cu S、Ni S） are mechanically incorporated into the electrode. Further research on electrode demonstrated that both mechanical doping and composite of Ni S can greatly improved the electrochemical performance of the electrodes.For mechanical doping electrode, results show that the iron electrode exhibited the best performance when the doping amount of Ni S was 10%, those electrode exhibits good discharge specific capacity performance. For composite electrode: Compound 5 %Ni S/Fe₃O₄ composites has better performance, its initial discharge capacity of the electrode up to 500⁵10 m Ah/g, discharge capacity reaches 300-390 m Ah/g at 1 C, Besides, the electrode has good cycle stability, the coulombic efficiency maintained in 80 %. The self-discharge of the electrode is only 4.1 % after 5 days.When adding three kinds of additives（CH3CSNH2, Na2S2O3, Na2S） into the electrolyte, it is found that the electrochemical performance of the Na2S2O3 additives is the best. Whose first discharge capacity reachs 480⁵00 m Ah/g and 250-290 m Ah/g at 0.1 C and 1 C, respectively. The electrochemical performance of the composite Fe₃O₄/Ni S electrode was found to be excellent by adding Na2S2O3 into the electrolyte, its initial discharge capacity of 0.1 C was as high as 700 m Ah/g.In view of the fact that the good electrochemical performance of the composite electrode, the electrode material was sintered at 200℃for 1 h, and it can be seen that the high rate discharge capacity and the efficiency of the electrode were improved. When adding three 5 mass% graphene（commercial graphene, acidificate graphene, graphene oxide） into the Fe₃O₄/Ni S composite, the results indicated that commercial graphene can increase the small rate capacity of electrode by 2 %. At the same time, the existence of graphene enhance the current efficiency of the electrode, its efficiency is above 90 % at 0.1 C.