Graphene‐functionalised Olivine Lithium Manganese Phosphate Derivatives for High Performance Lithium‐ion Capacitors

Abstract

AbstractLithium manganese phosphate nanoparticles (LiMnPO4; LMP) as well as the nickel‐doped (LMNP) and graphenised derivatives (G‐LMNP) were synthesized. Electrochemical characteristics of the materials were examined using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge‐discharge. Lithium ion capacitors (LIC) fabricated using LMP and composite materials as positive electrodes and activated carbon as the negative electrode, exhibited a specific capacitance of 60 F g−1 at a current load of 0.1 A g−1 for the AC//G‐LMNP LIC. Capacitance retention of 83 % was obtained by the AC//G‐LMNP LIC after 750 cycles, with a high specific power of 19 kW kg−1 at 0.5 A g−1.