Chemical Modification And Electrochemical Intercalation Of Lithium Into Carbon Nanotube

In this work, some chemical modification were carried out to the bundled multi-walled carbon nanotube (CNT) produced by a CVD method, and the change of the structure of the MWCNT was observed through the character of SEM, TEM, XRD, FT-IR, Raman, etc. The electrochemical Lithium intercalation property of the MWCNT as the anode of lithium ion battery was examined and compared with which of middle-phase carbon micro-bead (MCMB) for the commercial anode of lithium ion battery. It is observed that the MWCNT treatment with mixed-acid under ultrasonic showed a weaker etching effect to the graphite sheet than that treated by alkali at an elevated temperature, however the former gives a better reversible electrochemical Lithium-intercalation property. The sample treated with mixed-acid under ultrasonic showed a better reversible capacity of 214mAh/g than 144mAh/g of the purified MWCNT and 170mAh/g of the alkali annealing treated MWCNT. Based on the experimental results, a quasi-classical model was established to explain the reversible capacity of MWCNT. The calculated reversible capacity is between 124mAh/g ~ 186mAh/g which fits the research result well. Furthermore, a newly synthesized CNT filled with tin was characterized. Upon the electrochemical testing, it showed a better reversible capacity and coulomb efficiency.