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In this paper, medium temperature coal tar pitch was used as the raw material, and anthracene oil and wash oil were used to adjust the softening point as the diluents. Then remove QI from the soft pitch by the method of mixed solvent-centrifugal. Last, distill off the solvent to get the soft refined pitch, which the QI was less than 0.1%. It was carried out to investigate the effects of different diluents and its addition quantity on the softening point. And the effects such as solvent rate, the ratio of aromatic to aliphatic solvent were researched on QI content and the yield of refined soft pitch. Then, coal tar pitch, soft pitch and refined soft pitch were used to prepare coke through delayed coking, and the influences of different composition of raw materials, reaction temperature and system pressure were investigated on coke quality. Finally, after calcination, pitch coke, needle coke and metallurgical coke were packed into the lithium-ion batteries as the anodes separately, three kinds of carbons were determined the electrochemical performance. The result as follow.The optimal pretreatment process conditions were:30 wt% of anthracene oil was added, kerosene and wash oil were used as aliphatic solvent and aromatic solvent separately, and the ratio of them was 0.8, solvent ratio was more than 0.6, rotation speed was 2000rpm, centrifugation temperature was 80℃and centrifugation time was 10min, can obtain the refined soft pitch of QI≤0.1% and the more yield.The most optimal delayed coking process conditions were:soft refined pitch was heated to 450℃with temperature-programme, and maintain system pressure at 0.5MPa, then thermal polymerization time was 20h.Charge-discharge test showed that the first lithium capacity of needle coke samples was 386mAh/g, after forty times charge and discharge cycles lithium intercalation capacity didn’t shrink, and the cycle efficiency was more than 99%. CV analyzing showed that, all the cycle curves were coincided perfectly except the first one. This means that the needle coke has a good cycling stability. EIS analyzing showed that SEI film formed on the surface of needle coke was thin and dense, and the internal diffusion resistance of lithium ion in negative electrode is small, so needle coke has a good electrochemical transitivity.
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