Effect of synthesis parameters on the electrochemical properties of high-surface-area mesoporous titanium oxide with polypyrrole nanowires in the pores

Smith, Luke A. C. and Romer, Frederick and Trudeau, Michel L. and Smith, Mark E. and Hanna, John V. and Antonelli, David M. (2014) Effect of synthesis parameters on the electrochemical properties of high-surface-area mesoporous titanium oxide with polypyrrole nanowires in the pores. ChemElectroChem, 1 (12). pp. 2153-2162. ISSN 2196-0216

Abstract

This paper describes the synthesis and characterisation of high-surface-area mesoporous titanium oxides with polypyrrole nanowires within the pores, and the subsequent variation of synthesis parameters such as polymer-loading level and pore size to improve performance. These modifications are employed to improve the electron conductivity of the amorphous host and exploit the high internal surface areas of over 800 m2g−1 for potential use as a lithium battery cathode material, once fully optimised, with fast charge-transfer kinetics expected from the proximity of the vast majority of the redox sites at, or near, the surface of the inner pore walls. A full structural characterisation, in addition to electrochemical assessments, of the composite materials is presented and compared to the pristine mesoporous titanium oxide hosts. The best synthesis conditions were achieved with 5 % polymer loading and the largest pore sized host materials. Excessive polymer loading and smaller pore sizes lead to decreased performance, possibly due to inhibition of Li+ transport. The C18 templated TiO2 composite produced the best capacity retention at 58 % retention, and the C12 composite produced the highest initial capacity of 170 mAh g−1 by using a current density of 1 mAcm−2.