Angew Chem Int Ed Engl 2021 Jul 12. Epub 2021 Jul 12.
Wuhan University, College of Chemistry and Molecular Science, 299 Bayi Road, 430072, Wuhan, CHINA.
Noticeable pseudo-capacitance behaviour out of charge storage mechanism (CSM) has attracted intensive studies because it can provide both high energy density and large output power. Although cyclic voltammetry is recognized as the feasible electrochemical technique to determine it quantitatively in the previous works, the results are inferior due to uncertainty in the definitions and application conditions. Herein, three successive treatments, including de-polarization, de-residual and de-background, as well as a non-linear fitting algorithm are employed for the first time to calibrate the different CSM contribution of three typical cathode materials, LiFePO4, LiMn2O4 and Na4Fe3(PO4)2P2O7, and achieve well-separated physical capacitance, pseudo-capacitance and diffusive contributions to the total capacity. Read More