Synthesis of porous carbons from biomass for use as anode materials in lithium-ion batteries
Goh, Hui Xin
Date of Issue2016
School of Materials Science and Engineering
Due to the depletion of fossil fuels and the increasing demand in the field of electronics, highly efficient and environmental friendly energy storage systems such as lithium ion batteries have been attracting intense research interest lately. Carbon materials are currently the most commonly used anode materials for commercial lithium ion batteries. In this project, a facile and low cost method was used to successfully synthesize porous carbon materials from biomass resources and biowastes for use as an anode material in lithium ion batteries. Cobalt oxide Co3O4 nanoparticles were also synthesised in the carbon matrix derived from these biomass resources to produce a hybrid material. The method of synthesising this hybrid material generally involved impregnating the biomass with cobalt nitrate solution, followed by pyrolysis and thermal activation in air. These processes resulted in a highly porous carbon matrix with small Co3O4 nanoparticles uniformly dispersed in the structure. When tested as anode materials in lithium ion batteries, the dragonfruit peel sample exhibited a reversible capacity of 205 mAhg-1 while the longan shells sample exhibited a reversible capacity of 521 mAhg-1. The better electrochemical properties of the longan shells anode could be attributed to its unique sheet-like porous carbon structures. Such structures could prevent aggregation of the Co3O4 nanoparticles thereby enhancing electrode stability. The better capacity could also be due to the structures having more pores that served as additional reservoirs for lithium storage. Generally, both dragonfruit peel and longan shells showed good potential for use as anode materials in lithium ion batteries.
Final Year Project (FYP)
Nanyang Technological University