Resumen
Lithium iron phosphate (LiFePO4) is used as cathode material of rechargeable batteries, thanks to its high specific capacity, long cycle life, and high stability. In terms of electrical conductivity, LiFePO4 in nanowire shape is more efficient as compared to its spherical nanoparticle shaped counterpart due to its longer mean free path. However, LiFePO4 nanowires are still not available commercially. Therefore, a project aimed to produce highly crystalline LiFePO4 nanowires was conducted to solve this problem. It was done through coating LiFePO4 onto the surface of bacteria cellulose (BC) aerogel template produced by Acetobacter Xylinum sp., a gram-negative bacterium undergoes fermenting process with sago starch processing effluent (SSPE). At first, mixture of SSPE and Hestrin and Schramm (HS) medium at ratio of 1:1 (v/v) was used as the medium for a 14-day fermentation process. The results obtained show that BC produced in static culture at 30°C and pH 6 were nano-sized fibers with an average diameter of 29.40 nm. The harvested BC was then freeze-dried into bacterial cellulose aerogel (BCA). Brunauer-Emmett-Teller (BET) confirmed that the BCA contains 0.15 wt% BC has a surface area of 102.3m2/g. Meanwhile, FE-SEM micrographs proved that the same formulation was relatively less dense and more porous as compared to other formulations containing 0.05 wt%, 0.10 wt% and 0.20 wt% of BC. The BCA was later coated with LiFePO4 with the help of a uniform solution containing Li+, Fe2+ and PO4 3-ions, followed by undergoing calcination and sintering process. The final product obtained, LiFePO4 nanowires had a wire-liked structure with diameters ranged between 15-30 nm. Powder X-ray Diffraction (PXRD) and transmission electron microscopy (TEM) verified that the nanowires produced were coated with LiFePO4.