Preparation of Anode Active Material by Utilizing of Silica from Geothermal Sludge for Li-Ion Battery Application

摘要

Geothermal sludge (GS) from Dieng geothermal power plant has high Silica (SiO_2) content. Silica is a functional material in industrial application. This work reported preparation of anode active material from GS silica material for li-ion battery application. The anode active material was prepared by a series of processes as follows: acidification with 3% HCL, silica extraction with 3 M NaOH and 1 M HCL, silica purification with 37% HCL, metallothermal, and combustion. Chemical composition of the samples after metallothermal process (M1) contains the pure Si of 2.26% and increased after combustion process (M1P) to 10.60%. The electrochemical measurement was conducted using a cylindrical full cell battery 18650 with NCA as cathode. The specific discharge capacity for samples of M1P, M1 and graphite are 761.16, 605.56 and 314.45 mAhg~(-1), respectively. These results show that GS can be used as a raw material for anode active materials in li-ion battery applications.