Preparation And Modification Of Copper Based Anode Materials For Lithium Ion Batteries

Facing the rapid development of the epoch,traditional anode materials are further unable to satisfy people’s demand for the function of lithium-ion batteries.Thus,the development of a new type of anode material with excellent function and satisfying social demands has become a necessary way to solve the problem.The transition metal compounds copper sulfide（CuS）and copper oxide（CuO）have a good research prospect due to their excellent theoretical capacity（560 and 670 m Ah/g）,relatively smooth and obvious discharge and charging platform,and excellent safety performance.However,CuS and CuO anode materials unable guarantee the stability of their own structure during the cycle,and there are problems of huge capacity changes and poor cycle performance.Thus,reducing the volume change during the cycle becomes the key to improving the function of CuS and CuO.This paper designs and synthesizes flower-shaped CuS samples,obtains CuO samples on this basis,and realizes the optimization of both through the combination with other materials.The main research contents are as follows:Using copper chloride dihydrate（CuCl₂·2H₂O）,thiourea（CH₄N₂S）as raw materials,and polyethylene glycol（PEG）as surfactants,flower-like CuS samples were prepared.After 50 cycles,the flower-shaped CuS electrode can only maintain a discharge capacity of 62.1 m Ah/g,which unable satisfy the current stringent standards for the performance of the batteries.In order to improve the electrochemical function of flower-shaped CuS,this paper prepared CuS/Cu_7.2S₄and CuS/rGO samples on the basis of flower-shaped CuS electrodes.Compared with flower-shaped CuS,CuS/Cu_7.2S₄and CuS/rGO electrodes can maintain a higher discharge capacity after 50 cycles,which are 65.3 and 446.8m Ah/g,respectively.The use value of the battery has been improved to a certain degree.CuO and CuO/rGO samples were obtained using flower-shaped CuS as raw materials,and a comparative study was carried out between the two.The analysis results show that CuO/rGO samples have better electrochemical function.When CuO and CuO/rGO samples have been cycled for 50 times,the discharge capacity is 134.5and 304.7 m Ah/g,respectively.