Preparation And Electrochemical Properties Of Sn/C Composite Materials As Anode Materials For Lithium-Ion Batteries

On the growing of environmental protection conscious and developing of large scale equipment such as electric motor cars, the rapid development of high energy density and high power lithium-ion battery is urgent needed. Among the subtractive polarity electrode material composed of metal and charcoal, the most popular research is tin (tin oxide)/carbon composite. Compared to carbon matrix for tin or its oxide, ungraphitised carbon matrix has a higher void ratio, tin or tin oxide is able to permeate into the void, however, electro conductibility of ungraphitised carbon performs not well as carbon, so as to affect the total capacity of battery, restrict the heavy current's charge-discharge. As a result, the key of lithium-ion battery is its subtractive polarity electrode material. Now, researchers focus on the improvement of subtractive polarity electrode material to avoid capacity attenuation and reversible capacitance of condenser when the battery is on the charge-discharge of high magnification.There are many advantages of bamboo charcoal, one of charcoal materials, natural and renewable, low preparation temperature, simple processing technique, all above is helpful to consecrate petroleum, protect environment and fulfill the need of recycling economy.In this paper, construction of lowsintering bamboo charcoal from mao bamboo and its electrochemistry property were studied, by dipping in ethanol SnCl₂·2H₂O solution, then to prepare a certain subtractive polarity electrode of lithium-ion secondary battery by reductometry through NaBH₄. The subtractive polarity electrode is composed of Sn/C. The influence of Sn content to yield coefficient, microstructure and electrochemistry properties by the means of TEM, SEM, XRD, TG-DSC were studied. The results indicate that most Sn²⁺ permeate into the pore canal of bamboo charcoal by restoring to the original state Sn. When the mass ratio of composite to Sn is 42.5 to 100, reversible specific capacity of Sn/C composite electrode material is 555.1mAh·g^-1, capacity remained 423.8mAh·g^-1 after circling 20 times, which showed a preferable practicability.