화학공학소재연구정보센터
Electrochimica Acta, Vol.292, 759-768, 2018
Design of well-defined porous Ti2Nb10O29/C microspheres assembled from nanoparticles as anode materials for high-rate lithium ion batteries
Well-defined porous Ti2Nb10O29/C microspheres have been synthesized by a one-pot solvothermal method. The as-formed Ti2Nb10O29/C microspheres possess good dispersity and are constructed by interconnected nanoparticles. The unique porous microstructure and modification of conduction carbon can provide large electrode-electrolyte contact areas and improve the Li+ diffusion coefficient and electronic conductivity of Ti2Nb10O29/C microspheres, endowing them with excellent Li+ storage properties. Ti2Nb10O29/C porous microspheres can deliver prominent discharge capacity of 278.7, 239.7, 236.8, 220.5 and 208.1 mAh g(-1) at 1, 5, 10, 20, and 30 C, respectively. On the contrary, the discharge capacity of Ti2Nb10O29 porous microspheres can be quickly reduced from 278.6 to 140.5 mAh g(-1) (1 vs. 30C). Most importantly, Ti2Nb10O29/C microspheres display good rate capacity, such as 276.8 mAh g(-1) at 1 C, 245.6 mAh g(-1) at 10 C, 226.7 mAh g(-1) at 20 C, and even 217.9 mAh g(-1) at 30 C. It is deduced that the excellent rate performance is mainly caused by the pseudocapacitive effect. In addition, the discharge capacity of Ti2Nb10O29/C microspheres is retained to 186.7 mAh g(-1) at a high current density of 10 C after 200 cycle, with 89.5% retention of the 1st cycle capacity. (C) 2018 Elsevier Ltd. All rights reserved.