TiO2 shielded Si nano-composite anode for high energy Li-ion batteries: The morphological and structural study of electrodes after charge-discharge process
By Raj, Hari; Singh, Siddharth; Sil, Anjan
Published in Electrochimica Acta
2019
Abstract
Many efforts are being done to commercialize silicon (Si) as a high energy application anode for Li-ion batteries. However, still improvements are required at various levels from structural modification to fabrication process for commercializing Si as single anode material. In the present study, we report high improvement in the electrochemical performance of Si by shielding its surface with nano TiO2 particles. A layer of TiO2 nano particles is deposited on the surface of carbon coated nano Si by hydrothermal process to prevent the volume expansion during charge-discharge process. The sample is designated as Si/C–TiO2. The composite shows discharge capacity of 781 mAh g−1 after 200 cycles which was much higher than the capacity of pristine Si (23 mAh g−1) and carbon coated Si (Si/C) (215 mAh g−1) after 200 cycles. The Si/C–TiO2 composite has also shown higher capacity at all current rates from 100 mA g−1 to 2 A g−1 and a stable cycle life up to 200 cycles. The work also provides the morphological and structural study of electrodes after charge-discharge cycles conducted by field emission scanning electron microscopy, X-ray diffraction and X-ray photon spectroscopy techniques.