کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
193142 | 459763 | 2007 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Isothermal calorimetry investigation of Li1+xMn2−yAlzO4 spinel Isothermal calorimetry investigation of Li1+xMn2−yAlzO4 spinel](/preview/png/193142.png)
The heat generation of LiMn2O4, Li1.156Mn1.844O4, and Li1.06Mn1.89Al0.05O4 spinel cathode materials in a half-cell system was investigated by isothermal micro-calorimetry (IMC). The heat variations of the Li/LiMn2O4 cell during charging were attributed to the LiMn2O4 phase transition and order/disorder changes. This heat variation was largely suppressed when the stoichiometric spinel was doped with excess lithium or lithium and aluminum. The calculated entropy change (dE/dT) from the IMC confirmed that the order/disorder change of LiMn2O4, which occurs in the middle of the charge, was largely suppressed with lithium or lithium and aluminum doping. The dE/dT values obtained did not agree between the charge and the discharge at room temperature (25 °C), which was attributed to cell self-discharge. This discrepancy was not observed at low temperature (10 °C). Differential scanning calorimeter (DSC) results showed that the fully charged spinel with lithium doping has better thermal stability.
Journal: Electrochimica Acta - Volume 52, Issue 19, 25 May 2007, Pages 5837–5842