Preparation And Performance Of Carbon-coated SiO Anode Composites For Lithium Ion Battery

Nowadays,with the development of portable electronic equipment and electric vehicle industry,more and more researchers are committed to finding a kind of lithium ion battery cathode material with high energy density and long cycle life to meet the increasing needs of people.Alternatively,silicon monoxide(SiO)is considered a promising anode material for lithium ion batteries(LIBs)owing to its higher capacity and longer cycle life than those of graphite and silicon,respectively.Nevertheless,some drawbacks of SiO,including rapid capacity fading and poor initial coulombic efficiency owing to its low electrical conductivity and volume expansion,remain unsolved.To solve these problems,the carbon-coating is considered to be one of the simplest and effective modification methods.Therefore,by choosing commercial SiO as the matrix,this paper systematically studied how to better improve the effect of carbon coating from two different aspects,and the result can provide some reference for its industrial development.First of all,glucose was developed as a suitable and inexpensive carbon source to synthesize the SiO/C composite with a high performance.In addition,the effects of the calcination temperature and the amount of carbon source on the electrochemical performance of the SiO/C composite were investigated.The addition of 5 wt.% glucose and a calcination temperature of 800°C demonstrated the optimum conditions for SiO/C synthesis.The resultant SiO/C showed an initial charge capacity of 1259 mAh/g and a high initial coulombic efficiency of 71.9%.A charge capacity of 850 mAh/g after 100 cycles at 200 mA/g was achieved,demonstrating the best value of the SiO/C based materials.The composition changes of SiO under the calcination temperature played a significant role in the electrochemical performance.Meanwhile,in the 1000? heat treatment,after disproportionation reaction,the synthesised SiO/C composite material also shows a excellent electrochemical performance.In addition,in order to further determine the influence of different carbon sources on electrochemical performance,the electrochemical properties of SiO/C composites synthesized by different carbon source cladding were systematically studied based on the carbon source content of 5wt.%.The results show that the materials with asphalt as carbon source have the best cyclic stability.After 100 cycles,the capacity retention rate reached 95.23%,compared to the initial specific capacity.From the aspect of rate capability,the synthesis of SiO/C composite anode materials with phenolic resin as carbon source has the best rate capability.In the current density of 1 A/g and 2 g,it still can keep a reversible specific capacity of 1200 mAh/g and 1000 mAh/g,respectively.In this paper,The effects of the carbon source amount,calcination temperature and different carbon sources on the electrochemical performance of the obtained SiO/C materials were systematically investigated.By using cheap raw materials and industrialized mass production process to synthesis high performance of the SiO/C composite cathode materials,the result has a certain guiding role for the commercial development.