Properties of LiCoPO₄-non-graphitic carbon foam composites

By Lucangelo Dimesso,Christina Spanheimer,Dirk Becker,Wolfram Jaegermann
Published in Journal of Alloys and Compounds NULL 2014

Abstract

The properties of LiCoPO₄-non-graphitic carbon foams (LCP-NGCF) composites are reported. The composites are treated at 300 °C for different times (t, from 0 to 12 h) in air, then at 730 °C for 12 h in nitrogen. The diffraction analysis revealed LiCoPO₄ as major crystalline phase, Li₄P₂O7 and Co₂P (t = 0 h), Co₂P (t = 0 h) as secondary phases. The morphology consists of crystalline "islands" with spongy-like features on the surface (for t = 0 h) and with acicular crystallites of different dimensions (2 -20 μm) for t ≥ 0.1 h. The voltammetric curves show reduction potential values between 4.40 V and 4.60 V. The LCP-NGCF composites deliver a discharge specific capacity of 100 mAh g−1 (t = 0 h, discharge rate of C/25 and RT) and of 65 mAh g⁻¹ ( t > 0 h). The ac-impedance analysis reveal the formation of SEI-layer after high annealing times, which disfavors the kinetics of the Li-(de)intercalation processes.

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