A Carboranyl Electrolyte Enabling Highly Reversible Sodium Metal Anodes via a “Fluorine‐Free” SEI
A Carboranyl Electrolyte Enabling Highly Reversible Sodium Metal Anodes via a “Fluorine‐Free” SEI
复制标题
碳硼烷基电解质通过“无氟”SEI 实现高度可逆的钠金属阳极
DOI：
10.1002/anie.202208158
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Cheng, Lei
中科院分区：
文献类型：
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作者：
Tomich, Anton W.;Park, Jehee;Son, Seoung‐Bum;Kamphaus, Ethan P.;Lyu, Xingyi;Dogan, Fulya;Carta, Veronica;Gim, Jihyeon;Li, Tao;Cheng, Lei
由于缺乏兼容的电解液成分、枝晶生长以及对阳极相间化学的不了解，阻碍了实用化的钠金属电池(SMB)的实现。化学稳定性强的液体电解质有利于金属钠沉积和稳定的固体电解质界面(SEI)，是实现金属钠电池和无阳极电池的理想选择。在这里，我们提出了一种利用[HCB11H11]1−阴离子的新型无氟电解液的高级表征。使用该电解液的对称型钠电池在电流密度为2.0mA cm-2时，过电位为0.032 V，在半电池配置下的库仑效率为99.5 %。手术后电极的表面特征表明，没有树枝状钠成核和令人惊讶的稳定的无氟SEI。此外，弱离子配对被认为是成功开发无氟钠电解质的关键。
Realization of practical sodium metal batteries (SMBs) is hindered due to lack of compatible electrolyte components, dendrite propagation, and poor understanding of anodic interphasial chemistries. Chemically robust liquid electrolytes that facilitate both favorable sodium metal deposition and a stable solid‐electrolyte interphase (SEI) are ideal to enable sodium metal and anode‐free cells. Herein we present advanced characterization of a novel fluorine‐free electrolyte utilizing the [HCB11H11]1−anion. Symmetrical Na cells operated with this electrolyte exhibit a remarkably low overpotential of 0.032 V at a current density of 2.0 mA cm−2and a high coulombic efficiency of 99.5 % in half‐cell configurations. Surface characterization of electrodes post‐operation reveals the absence of dendritic sodium nucleation and a surprisingly stable fluorine‐free SEI. Furthermore, weak ion‐pairing is identified as key towards the successful development of fluorine‐free sodium electrolytes.