Journal of Power Sources, Vol.288, 176-186, 2015
High-rate intercalation capability of NaTi2(PO4)(3)/C composite in aqueous lithium and sodium nitrate solutions
The nanodispersed NaTi2(PO4)(3)/C composite containing 20-25 wt.% of in-situ formed carbon, was synthesized by gel combustion procedure followed by a heat treatment at 650, 700 and 750 degrees C. The samples calcined at 700 and 750 degrees C displayed crystalline nasicon structure. They were subjected to the investigation of intercalation/deintercalation kinetics in aqueous NaNO3 and LiNO3 solutions, using cyclic voltammetry and galvanostatic charging/discharging measurements. As regards to the effect of electrolyte composition, the reactions were evidenced to be roughly twice faster in sodium nitrate than in lithium nitrate solution. Among the samples treated at 700 and 750 degrees C, better performance was evidenced for the sample treated at lower temperature. Coulombic capacity in NaNO3 solution at charging rate 1C amounted to similar to 70 mAh g(-1) and similar to 55 mAh g(-1) for the sample calcined at 700 and 750 degrees C, respectively, and displayed surprisingly slight dependence on charging rate up to even 100C. (c) 2015 Elsevier B.V. All rights reserved.
Keywords:Aqueous electrolyte;Gel-combustion synthesis;Nasicon;NaTi2(PO4)(3)/C composite;Sodium-ion batteries