Rechargeability of Li-air cathodes pre-filled with discharge products using an ether-based electrolyte solution: implications for cycle-life of Li-air cells
Rechargeability of Li-air cathodes pre-filled with discharge products using an ether-based electrolyte solution: implications for cycle-life of Li-air cells
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DOI：
10.1039/c3cp51112j
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发表时间：
2013-01-01
影响因子：
3.3
通讯作者：
Gasteiger, Hubert A.
中科院分区：
文献类型：
--
作者：
Meini, Stefano;Tsiouvaras, Nikolaos;Gasteiger, Hubert A.
目前使用的电解质溶液和碳载体在非水锂-氧电池中的充电-放电期间的不稳定性可导致除所需Li 2 O2以外的放电产物，例如Li 2CO 3，其被认为降低循环寿命。类似地，在含有H2O和CO2杂质的O-2气氛中放电将导致LiOH和Li 2CO 3放电产物。因此，在这项工作中，我们研究了预填充有四种可能的锂空气电池放电产物，即Li 2 O2，Li 2CO 3，LiOH和Li 2 O的模型阴极的可再充电性。使用在线电化学质谱法（OEMS），我们确定了充电电压和预填充电极充电时产生的气体，从而确定了形成/电氧化反应的可逆性。我们表明，Li 2 O2是唯一的可逆放电产物在醚基电解质溶液中，和Li 2CO 3，LiOH，或Li 2 O的形成是不可逆的和/或与电解质溶液或碳在其氧化过程中反应。
The instability of currently used electrolyte solutions and of the carbon support during charge-discharge in non-aqueous lithium-oxygen cells can lead to discharge products other than the desired Li2O2, such as Li2CO3, which is believed to reduce cycle-life. Similarly, discharge in an O-2 atmosphere which contains H2O and CO2 impurities would lead to LiOH and Li2CO3 discharge products. In this work we therefore investigate the rechargeability of model cathodes pre-filled with four possible Li-air cell discharge products, namely Li2O2, Li2CO3, LiOH, and Li2O. Using Online Electrochemical Mass Spectrometry (OEMS), we determined the charge voltages and the gases evolved upon charge of pre-filled electrodes, thus determining the reversibility of the formation/electrooxidation reactions. We show that Li2O2 is the only reversible discharge product in ether-based electrolyte solutions, and that the formation of Li2CO3, LiOH, or Li2O is either irreversible and/or reacts with the electrolyte solution or the carbon during its oxidation.