Simple, green and cost effective method is used for the synthesis of TiO2 nanoparticles, wherein remnant water (ideally kitchen waste) collected from soaked Bengal gram beans (Cicer arietinum L.) extract is reacted with TiCl4. Biosynthesized TiO2 (Bio-TiO2) nanoparticles with uniform size distribution (free of aggregation even after calcination) were obtained as a result of the stabilizing molecules naturally present in the extract. The morphology, crystal structure and phase composition, specific surface area and pore size distribution of Bio-TiO2 were systematically investigated by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and BET surface area measurement system. Li-insertion properties were evaluated as anodes in the half-cell configuration (Li/Bio-TiO2) and it is found to demonstrate reversible insertion of 0.61 mol at a current density of 33 mA g−1. The half-cell displayed a good cyclability and retained 98% of its initial reversible capacity even after 60 galvanostatic cycles.