Electrode Performance of Sodium and Lithium-Type Romanechite
Electrode Performance of Sodium and Lithium-Type Romanechite
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钠型和锂型罗马石的电极性能
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
Y. Sakurai
中科院分区：
文献类型：
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作者：
Masayuki Tsuda;H. Arai;Y. Nemoto;Y. Sakurai
我们研究了作为可充电锂电池正极材料的锰镁石，这是一种具有（2 × 3）隧道结构的二氧化锰，其中包括阳离子和水。我们选择了钠型和锂型锰榴石，它们比已经报道的钡型锰榴石更轻，并获得了大的放电容量。当我们第一次充电的锂型romanechite，我们获得了约200 mAh g-1的大的首次放电容量。放电曲线形状是独特的，在3.7、3.0和2.5V（相对于Li/Li +）处具有平台。当我们使用2.5V平台将材料放电至2.0V时，循环性差。然而，通过仅使用3.7和3.0 V平台，我们能够在几乎没有容量损失的情况下循环它，并获得约80 mAh g-1的可充电容量。X射线衍射分析表明，在2.5 V平台处存在结晶度变化。我们认为这种变化是锂型罗马石循环性差的原因。
We studied romanechite, which is a kind of manganese dioxide with a (2 × 3) tunnel structure that includes cations and water, as a positive electrode material for rechargeable lithium batteries. We selected sodium and lithium-type romanechite, which are lighter than the already reported barium-type romanechite, and obtained large discharge capacities. When we first charged lithium-type romanechite, we obtained a large first discharge capacity of about 200 mAh g -1 . The discharge profile shape was unique with plateaus at 3.7, 3,0, and 2.5 V (vs. Li/Li + ). The cyclability was poor when we discharged the material to 2.0 V using the 2.5 V plateau. However, by using only the 3.7 and 3.0 V plateaus, we were able to cycle it with little capacity loss and obtain a rechargeable capacity of about 80 mAh g -1 . X-ray diffraction analysis showed that there was a crystallinity change at the 2.5 V plateau. We consider this change to be the reason for the poor cyclability of lithium-type romanechite.