• Pandolfo, Tony
• Bourgeois, Laure

Abstract

The preparation of a stoichiometric dispersion of nanostructured LiFePO4 clusters intimately bound within a carbon matrix is described. A synthetic process, utilising a novel single molecular source precursor, was developed and used to infiltrate a structured mesoporous carbon template. Subsequent optimisation of the infiltration process, reductive pyrolysis and secondary dispersion of the active materials for electrode coatings gave highly effective LiFePO4/C composite electrodes suitable for high power applications. Extensive electrochemical performance evaluation, at rates exceeding 20 C, confirmed a resilient stable material capable of delivering exceptional high rate performance which is attributed to the periodic, interconnected mesopores (5-6 nm) that also serve as electrolyte reservoir giving improved ionic accessibility. Galvanostatic charge-discharge cycling demonstrated the materials excellent stability and high utilization, with a specific discharge capacity of 163 Ah kg-1 (close to theoretical unity of 170 Ah kg-1) at 0.2C and 128 Ah kg-1 at 23 C.These materials are well suited for application in high power energy storage devices including high power lithium batteries and hybrid devices.

Topics

• pyrolysis
• impedance spectroscopy
• dispersion
• surface
• cluster
• Carbon
• composite
• Lithium