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The compatibility between the electrolyte of lithium bis( oxalato) borate (LiBOB) and the materials of cathode and anode as well as the rate capability of the cathode material at room temperature was studied by cyclic vohammetry, electrochemical impedance spectroscopy (EIS) and charge-discharge cycle testes. The effect of acetonitrile(ACN) on electrochemical performance of the electrolyte of LiBOB was investigated. The results showed that LiFePO4 in the electrolyte of LiBOB showed a remarkable electrochemical performance. The cycle performance was improved when the ACN was added. The anode of shapecontrolled micrographite ( SCMG) formed stable and effective SE1 film in the electrolyte of LiBOB. The cycle performance declined, while the reversible capacity of the first cycle was promoted a little when ACN was added. [ABSTRACT FROM AUTHOR]

Abstract: The geometric and electronic structure of Li15Si4 is studied as the full-lithiated phase of Si anode by first principle calculations within the framework of the density functional theory. The results reveal that the volume change of Si host after Li-intercalation is 269.3%. Besides, the Si host shows metallic properties with the Fermi level crossing the partial-occupied bands after Li intercalation and the chemical bands of Li–Si are found to be polar covalence with some ionicity caused by the partial electron transfer from Li to Si atoms. Further, the deterioration factor of Si anode is analyzed theoretically to be the flaking of active Si off the current collector, which is in agreement with the experimental knowledge. The average intercalation voltage is also calculated to be 0.304V which is close to the experimental value 0.1–0.2V. Moreover, the results demonstrate that the theoretical quantum computations could be a meaningful tool in the research field of Si-based anode. [Copyright &y& Elsevier]