Pressure Dynamics in Metal-Oxygen (Metal-Air) Batteries: A Case Study on Sodium Superoxide Cells
Pressure Dynamics in Metal-Oxygen (Metal-Air) Batteries: A Case Study on Sodium Superoxide Cells
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DOI：
10.1021/jp4099478
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发表时间：
2014-01-23
影响因子：
3.7
通讯作者：
Adelhelm, Philipp
中科院分区：
文献类型：
--
作者：
Hartmann, Pascal;Gruebl, Daniel;Adelhelm, Philipp
金属氧电池中的电化学反应沿着气态氧的消耗或释放。我们提出了一种新的方法来研究电极反应和传输现象，在金属氧电池通过测量压力动态在一个封闭的储气室以上的氧电极。该方法通过在二甘醇二甲醚（二甘醇二甲醚）和三氟甲磺酸钠（NaOSO 2CF 3，NaOTf）的电解质中形成超氧化钠（NaO 2）的室温钠-氧电池来举例说明。实验得到了一维多物理场连续模型的微观动力学模拟的支持。在超过30个循环的恒电流循环期间，在放电/充电时观察到恒定的氧消耗/释放速率。每个氧分子的转移电子数计算为1.01 +/- 0.02和1.03 +/- 0.02，分别用于放电和充电，确认氧反应产物的性质为超氧化物O-2（-）。在低扫描速率的循环伏安法实验中观察到相同的比率（
Electrochemical reactions in metal-oxygen batteries come along with the consumption or release of gaseous oxygen. We present a novel methodology for investigating electrode reactions and transport phenomena in metal-oxygen batteries by measuring the pressure dynamics in an enclosed gas reservoir above the oxygen electrode. The methodology is exemplified by a room-temperature sodium-oxygen battery forming sodium superoxide (NaO2) in an electrolyte of diethylene glycol dimethyl ether (diglyme) and sodium trifluoromethanesulfonate (NaOSO2CF3, NaOTf). The experiments are supported by microkinetic simulations with a one-dimensional multiphysics continuum model. During galvanostatic cycling over 30 cycles, a constant oxygen consumption/release rate is observed upon discharge/charge. The number of transferred electrons per oxygen molecule is calculated to 1.01 +/- 0.02 and 1.03 +/- 0.02 for discharge and charge, respectively, confirming the nature of the oxygen reaction product as superoxide O-2(-). The same ratio is observed in cyclic voltammetry experiments with low scan rate (