Annealing atmosphere dependant properties of biosynthesized TiO2 anode for lithium ion battery application

The present work demonstrates the synthesis of in situ carbon incorporated TiO 2 nanoparticles (Bio-TiO 2 /C) and bare Bio-TiO 2 from low cost and eco-friendly materials, wherein Bengal gram beans ( Cicer arietinum L.) extract containing bio-molecules is used as complexing agent to stabilize and engineer Bio-TiO 2 /C used as anode for lithium ion battery application. The influence of annealing atmosphere (argon and air) on the formation of carbon anchored biosynthesized TiO 2 nano-spheres is investigated systematically. Interestingly, selective formation of TiO 2 /C nano-spheres is observed in argon atmosphere, while annealing in air leads to the formation of carbon free TiO 2 nanoparticles. The gram bean extract containing biomass helps to inhibit the aggregation, leading to uniform size distribution of TiO 2 nanoparticles. These biomasses convert into carbon after calcination of as prepared Bio-TiO 2 in argon atmosphere (Bio-TiO 2 /C), and in air calcinations, these biomasses are completely oxidised and form bare Bio-TiO 2 . The resulting products TiO 2 /C and TiO 2 are characterized using thermogravimetry analyzer, X-ray diffraction, transmission electron microscopy, Raman spectrophotometer, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Furthermore, the prepared TiO 2 /C and TiO 2 are investigated as electrodes for lithium ion battery. The charge/discharge performance of TiO 2 /C shows an initial reversible capacity of 208 mA h g −1 at a current density of 33 mA g −1 , which is higher than TiO 2 nanoparticles (197 mA h g −1 ). The cycling study exhibit TiO 2 /C based electrode retaining about 100 % of reversible capacity after 60 cycles at same current density, which is 3 % higher than the TiO 2 nanoparticles based electrode.