添加剂对铁镍电池负极性能的影响

发布时间：2018-06-15 05:50

  本文选题：电极添加剂 + 电解液添加剂　； 参考：《哈尔滨工业大学》2016年硕士论文

【摘要】：面对如今新能源电动汽车以及电力设备的市场需求,由于铁镍电池具有高的理论容量、绿色环保、循环寿命长、安全、耐滥用、耐过充性能好等优势,在近几年备受企业以及高校研究者的关注及重视。但是对于铁电极来说,现在仍然存在着电极的钝化、析氢严重等问题。本文从材料的制备方法、电极添加剂、电解液添加剂和优化电极性能四个方面进行研究,并取得了一些研究成果。利用沉淀氧化法制备出了纳米的Fe_3O_4材料,其纯度较高,颗粒粒径在20nm左右,电化学活性较大,在0.1 C放电时电极的容量高达250 mAh/g。电极中掺5%的三种硫化物(FeS、CuS、NiS)添加剂,发现掺杂NiS的电极的电化学性能更优异一些。进而对电极进行探究,发现不论机械掺杂还是复合NiS的存在都能使得电池的电化学性能提高,对于机械掺杂电极来说:掺杂10%NiS的电极电化学性能最好,0.1 C放电比容量高达407 mAh/g。对复合电极,发现复合5%NiS的Fe_3O_4/NiS电极具有较优的性能,0.1 C放电时容量高达500~510 mAh/g,1 C放电达到300-390 mAh/g,并且此电极不易析氢,循环稳定性好,充放电库仑效率维持在80%以上。电极在静置5天后开路电压仅仅衰减了4.1%。研究加入CH3CSNH2、Na2S2O3、Na2S电解液添加剂发现,添加Na2S2O3的效果最好,0.1 C放电比容量能够达到480~500 mAh/g,1 C放电,容量在250-290 mAh/g左右。向三种复合电极电解液中加入Na2S2O3,发现复合5%NiS的Fe_3O_4/NiS电极电化学性能好,在0.1 C下的首次放电容量高达700 mAh/g。鉴于复合电极的电化学性能良好,在此电极的基础上对电极材料进行了烧结处理,发现烧结仅仅提高了电极的大倍率放电容量和效率。向复合5%NiS的Fe_3O_4/NiS复合材料中分别加入了三种5 mass%石墨烯(商业石墨烯、酸化石墨烯、氧化石墨烯)材料,发现材料中掺入商业石墨烯可以使电极的小倍率容量提升2%,同时石墨烯的存在提升了电极的充放电效率,使得电极的充放电效率在90%以上。
[Abstract]:In the face of the market demand of new energy electric vehicles and power equipment, due to the advantages of high theoretical capacity, green environmental protection, long cycle life, safety, anti-abuse, good overcharge resistance and so on, iron and nickel batteries have many advantages, such as high theoretical capacity, environmental protection, long cycle life, etc. In recent years, the enterprise and the university researcher's attention and attention. However, for iron electrodes, there are still some problems such as passivation and hydrogen evolution. In this paper, the preparation of materials, electrode additives, electrolyte additives and optimization of electrode properties are studied, and some research results have been obtained. Fe3O4 nanocrystalline Fe3O4 was prepared by precipitation oxidation method. Its purity is high, the particle size is about 20nm, the electrochemical activity is high, and the capacity of the electrode is up to 250mAh/ g at 0.1C discharge. It is found that the electrode doped with NiS has better electrochemical performance. It is found that both mechanical doping and composite NiS can improve the electrochemical performance of the battery. For the mechanically doped electrode, the electrochemical performance of the electrode doped with 10NiS is the best. The discharge specific capacity of the electrode doped with 10NiS is up to 407mAh/ g. For the composite electrode, it is found that the composite 5NiS Fe3O-1 / NiS electrode has better performance when discharging at 0.1 C, the discharge capacity is as high as 500 ~ 510mAh/ g ~ (-1) C, and the discharge capacity of the electrode is 300-390 mg / g, and the electrode is not easy to release hydrogen, has good cycling stability, and the charge / discharge Coulomb efficiency is above 80%. The open circuit voltage of the electrode only attenuated 4.1 after 5 days of statics. The addition of Ch _ 3CSNH _ 2H _ 2N _ 2S _ 2O _ 3 Na _ 2S electrolyte has been studied. It is found that adding Na _ 2S _ 2O _ 3 has the best effect on the discharge specific capacity of 0.1C with discharge capacity of 480 ~ 500mAh/ g ~ (-1) C, about 250-290 mAh/g. Adding Na _ 2S _ 2O _ 3 into the electrolyte of three kinds of composite electrode, it is found that the Fe3O _ 4 / NiS electrode of composite 5NiS has good electrochemical performance, and the initial discharge capacity at 0.1 C is as high as 700mAh/ g. In view of the good electrochemical performance of the composite electrode, the electrode material was sintered on the basis of this electrode. It was found that sintering only improved the discharge capacity and efficiency of the electrode at a large rate. Three kinds of 5 mass% graphene (commercial graphene, acidified graphene, graphene oxide) were added to the Fe3O4 / NiS composite. It is found that commercial graphene can increase the capacity of electrode by 2%, and the efficiency of electrode charge and discharge is increased by 90% because of the presence of graphene.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM912
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本文编号：2020937