Analysis of the self-discharge process in LiCoPO4 electrodes: bulks

作者：Manzi J; Vitucci F M; Paolone A; Trequattrini F; Di Lecce D; Panero S; Brutti S^*

来源：Electrochimica Acta, 2015, 179: 604-610.

DOI：10.1016/j.electacta.2015.03.071

• LiCoPO4
• self-discharge
• high voltage cathode
• Synchrotron XRD
• Synchrotron FT-IR

LiCoPO4 (LCP) is a promising high voltage cathode for next-generation high energy Li-ion batteries. However, once electrochemically de-lithiated, it suffers from a spontaneous self-discharge process in open circuit conditions. Here we present our systematic study about the phase composition and structural changes of LCP electrodes upon charging and self-discharging processes by ex situ synchrotron X-ray diffraction and Fast-Fourier Transform Infrared Spectroscopy (FT-IR) analyses. Various initial charging states and different current rates have been studied. Our investigation highlights large structural alterations of the de-lithiated CoPO4 phase upon self-discharge. However, after 160 hours with open circuit the pristine LCP structure is recovered. The electrochemically de-lithiated phase reincorporates lithium by a spontaneous reduction reaction releasing gaseous CO2 and likely degrading the electrolyte molecules.

• 出版日期2015-10-10