Nanotubular Nickel Hydrosilicate and Its Thermal Annealing Products as Anode Materials for Lithium Ion Batteries

— We have studied the performance of nanotubular nickel hydrosilicate and its derivatives as a negative electrode of lithium ion batteries. Nickel hydrosilicate with the composition Ni 3 Si 2 O 5 (OH) 4 was synthesized under hydrothermal conditions (350°C, 14 MPa, 10 h). Its derivatives were prepared by thermal annealing at temperatures of 400, 600, and 1000°C. In this process, the tubular structure of the particles persisted up to 600°C, whereas at 1000°C well-crystallized Ni 2 SiO 4 was formed. Charge/discharge cycles were performed in the voltage range 0.05–3 V at a specific current of 10 mA/g. Heat treatment was shown to increase discharge capacity and reversible capacity in the first cycle. The highest performance was offered by the material heat-treated at 400°C: its discharge capacity reached 678 mAh/g and its reversible capacity was 58% in the first cycle and 85% in subsequent cycles.