In Situ Optical Imaging of Sodium Electrodeposition: Effects of Fluoroethylene Carbonate
In Situ Optical Imaging of Sodium Electrodeposition: Effects of Fluoroethylene Carbonate
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DOI：
10.1021/acsenergylett.7b00500
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发表时间：
2017-09-01
影响因子：
22
通讯作者：
Mullins, C. Buddie
中科院分区：
文献类型：
--
作者：
Rodriguez, Rodrigo;Loeffler, Kathryn E.;Mullins, C. Buddie
钠电沉积物和气体析出的形态进行了研究，在一个系统中，包括一个对称的Na/Na光电池，数字显微镜，和电化学工作站。碳酸乙烯酯（EC），碳酸二乙酯（DEC），和碳酸丙烯酯（PC）中的钠沉积产生大量的气体和脆弱的，多孔的枝晶。氟代碳酸亚乙酯（FEC）的使用大大减少了沉积过程中的析气，并表现出上级的循环性能，阻抗，和循环效率，当它被用作与DEC（1：1体积）的共溶剂;然而，多孔沉积持续。飞行时间的二次离子质谱显示，在FEC/DEC中形成的固体电解质界面相，与EC/DEC电解质相比，更厚，更富含NaF，并形成不太致密的聚合物有机层。
The morphologies of sodium electrodeposits and gas evolution were studied in a system comprising a symmetrical Na/Na optical cell, a digital microscope, and an electrochemical workstation. Sodium deposition in ethylene carbonate (EC), diethyl carbonate (DEC), and propylene carbonate (PC) generated large volumes of gas and fragile, porous dendrites. The use of fluoroethylene carbonate (FEC) greatly reduced gassing during deposition and demonstrated superior cycling performance, impedance, and cycling efficiency when it was used as a cosolvent with DEC (1:1 vol); however, porous depositions persisted. Time of flight secondary-ion mass spectrometry revealed that the solid-electrolyte interphase formed in FEC/DEC, in contrast with the EC/DEC electrolyte, is thicker, richer in NaF, and forms a less dense polymer organic layer.