Morphology Evolution during Delithiation of Li-Pb Alloys: Oscillatory Electrochemical Behavior
Morphology Evolution during Delithiation of Li-Pb Alloys: Oscillatory Electrochemical Behavior
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DOI：
10.1149/2.0161906jes
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发表时间：
2019
影响因子：
3.9
通讯作者：
K. Geng;Minglu Liu;Yusi Xie;Ashlee Aiello;Erin Karasz;K. Sieradzki
中科院分区：
文献类型：
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作者：
K. Geng;Minglu Liu;Yusi Xie;Ashlee Aiello;Erin Karasz;K. Sieradzki
本文报道了用Pb颗粒和片状电极电化学锂化制备的Li-P球在脱锂后的形态演变研究。为了确定Li，<$D Li的本征扩散率随合金成分的变化，进行了电化学滴定和光测时间测定，其范围为10 − 12 - 10 − 10 cm 2 s − 1。研究了恒电流和恒电位脱合金条件下的形貌演变。对于颗粒电极，我们观察到对应于Kirkendall空隙、负枝晶、空隙结节和常规双连续纳米多孔结构的脱合金形态。在铅片的情况下，在恒电流脱合金条件下获得类似的脱合金形态，然而，在恒电位脱合金的情况下，我们没有观察到大体积双连续纳米多孔结构的形成。对于锂化到对应于Li 8 Pb 3相的组成并在电流密度为1.01 mAcm − 2时恒电流去合金化的Pb片，观察到电压振荡，周期为70-90 s，振幅范围为20-130 mV。还观察到恒电位去合金化在1 V相对于Li + /Li的电流振荡。这些振荡的可能机制进行了讨论，并归因于盐膜沉淀和剥离过程。当在电化学反应性元素的选择性溶解的范围内时，导致自组织结构。在脱合金扩散传质过程中
Wereportonastudyofmorphologyevolutionfollowingde-lithiationofLi-Pballoys,producedbytheelectrochemicallithiationofPbparticulateandsheetelectrodes.ElectrochemicaltitrationandtimeofflightmeasurementswereperformedinordertodeterminetheintrinsicdiffusivityofLi,¯ D Li , as a function of alloy composition, which ranged from 10 − 12 –10 − 10 cm 2 s − 1 . Morphology evolution was studied under conditions of galvanostatic and potentiostatic dealloying. For the particulate electrodes, we observed dealloyed morphologies corresponding to Kirkendall voids, negative dendrites, void nodules and conventional bicontinuous nanoporous struc- tures. In the case of Pb sheets, similar dealloyed morphologies were obtained under galvanostatic dealloying conditions, however, in the case of potentiostatic dealloying, we did not observe the formation of large volume bicontinuous nanoporous structures. For Pb sheets lithiated to a composition corresponding to the Li 8 Pb 3 phase and galvanostatically dealloyed at current densities ∼ 1 mAcm − 2 , voltage oscillations were observed with periods of 70–90 s and amplitudes ranging from 20–130 mV. Current oscillations were also observed for potentiostatic dealloying at 1 V vs Li + /Li. The possible mechanism of these oscillations is discussed and attributed to a salt film precipitation and lift-off process. when in the range of selective dissolution of electrochemically reactive element results in self-organized structures. during dealloying diffusion mass transport