Voltage-Mediated Enhances Lithium-Ion Storage in LiTiOPO₄ by Combustion Method

LiTiOPO₄ was prepared by solid-phase combustion method using citric acid as fuel. The LiTiOPO₄ materials were characterized by X-ray diffraction test (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The XRD test showed that the synthesized samples were pure phases and the addition of different weight fractions of the combustion agent citric acid did not change the phase structure of the LiTiOPO₄. The microscopic observations revealed that the LiTiOPO₄ prepared after the addition of citric acid as a combustion agent was a sheet-like stacked structure. The electrochemical test results showed that the rate discharge capacity of LiTiOPO₄ anode at 5000 mA g⁻¹ maintains 184.7 mAh g⁻¹ in the voltage range of 0.01–3.0 V and keeps at 147.2 mAh g⁻¹ after 500 cycles. The LiTiOPO₄ anode exhibits excellent cycling stability and good reversibility, which is attributed to the high crystallinity of LiTiOPO₄ prepared by solid-phase combustion and the lamellar stacked layer structure that facilitates lithium-ion insertion/de-insertion.