Effect of pre-lithiation degrees of mesocarbon microbeads anode on the electrochemical performance of lithium-ion capacitors
作者：Jin Zhang , Zhiqiang Shi*, Chengyang Wang*
關鍵字：Li-ion capacitors, Pre-lithiation degrees, Phase transition, Mesocarbon microbeads electrode, Activated carbon electrode
論文來源：期刊
具體來源：Electrochimica Acta
發表時間：2014年
Lithium ion capacitors are assembled with pre-lithiated mesocarbon
microbeads (LMCMB) anode and activated carbon (AC) cathode. The effect of
pre-lithiation degrees on the crystal structure of MCMB electrode and the
electrochemical capacitance behavior of LIC are investigated by X-ray diffraction
(XRD) and the charge-discharge test of three-electrode cell. The structure of
graphite still maintained when the pre-lithiation capacity is less than 200 mAh/g,
phase transition takes place with the increase of pre-lithiation capacity from
250 mAh/g to 350 mAh/g. Pre-lithiation degrees of MCMB negative electrode
greatly affect the charge-discharge process and behavior, which impact on the
electrochemical performance of LIC. The LIC with pre-lithiation capacity of 300
mAh g-1 has the optimal electrochemical performance. The energy density of
LIC300 is up to 92.3 Wh /kg, the power density as high as 5.5 kW/kg and the
capacity retention is 97.0% after 1000 cycles. The excellent electrochemical
performance benefits from the appropriate pre-lithiation capacity of negative electrode.
The appropriate pre-lithiation ensures the working voltage of negative
electrode in low and relative stable charge-discharge platform corresponding to
the mutual phase transition from the second stage graphite intercalation
compound (LiC12) to the first stage graphite intercalation compound (LiC6). The
stable charge-discharge platform of negative electrode is conductive to the sufficient
utilization of AC positive electrode.