Study On The Boron-doped Furan Resin Carbon As Anode Materials For Rechargeable Lithium-ion Batteries

Currently, carbon is still the major commercial anode materials for lithium ion batteries at present.To meet higher demand,exploring noval carbon materials has become a hot research.High temperature heat treated furan resin carbon and high temperature purifing treated furan resin carbon were prepared by high temperature(2000℃～3000℃) heat treated furan resin containing5wt%boric acid with an ambience of high purity argon or chlorine-containing gas after carbonization.The results indicate that furan resin pyrolytic carbon is an amorphous carbonaceous materials with lots of nanopores. The electrochemical performance of furan resin pyrolytic carbon is effectively improved when the level of boric acid is up to5wt%, which shows the highest reversible capacity (378.2mAh/g) at the first cycle, and the highest capacity retention (86.8%) after50cycles.However, it still has some disadvantages such as large irreversible capacity and voltage hysteresis.The structure order and cystal size are improved as the increase of heat-treated temperature. And boron doping improves the structure oder and cystal size more efficiently. Chlorine has purify effect and the impurities are removed effectively, which benefits the growth of crstal size, especially La, and the enhancement of structure order.As the increase of heat treated temperature, the high tempreture heat treated furan resin carbon shows higher reversible capacity and irreversible capacity, which leads to low coulombic efficiency(<80%) at the first cycle. And boron doping improves the reversible capacity of furan resin carbon more effectively, while the irreversible capacity becomes much higher than boron free furan resin carbon as the increase of heat treated temperature.Compared with the high heat treated furan resin carbon, the high temperature purification treated furan resin carbon obtains better electrochemical performances, which shows a7%increase in coulombic efficiency, above30mAh/g decrease in irreversible capacities as well as about57mAh/g increase in reversible capacities respectively, and no capacity fading after50cycles. However, the rate discharge performances get lower because of the lager particle size and cystal size. The boron doped resin carbon prepared with high temperature purifing treatment obtains the best electrochemical performance. It shows361.8mAh/g in the reversible capacity after50cycles, and317mAh/g in the reversible capacity at0.5C discharge rate, which basically reaches the demand of the present commercial artificial anode materials for lithium ion batteries.