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Download fileNitrofullerene, a C60-based Bifunctional Additive with Smoothing and Protecting Effects for Stable Lithium Metal Anode
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posted on 2019-11-08, 19:33 authored by Zhipeng Jiang, Ziqi Zeng, Chengkai Yang, Zhilong Han, Wei Hu, Jing Lu, Jia XiePractical
applications of lithium metal anodes are gravely impeded
by inhomogeneous lithium deposition, which results in dendrite growth.
Electrolyte additives are proven to be effective in improving performance
but usually serve only a single function. Herein, nitrofullerene is
introduced as a bifunctional additive with a smoothing effect and
forms a protective solid electrolyte interphase (SEI) layer on stable
lithium metal anodes. By design, nitro-C60 can gather on
electrode protuberances via electrostatic interactions and then be
reduced to NO2– and insoluble C60. Next, the C60 anchors on the uneven groove of the lithium
surface, resulting in a homogeneous distribution of Li ions. Finally,
NO2– anions can react with metallic Li
to build a compact and stable SEI with high ion transport. With a
5 mM nitro-C60 additive, Li–Li symmetric cells show
superior cycle stability in both carbonate and ether electrolytes,
Li–sulfur batteries with a high cathode loading (10.6 mg cm–2, 6 mAh cm–2) can achieve improved
cycle retention of 63.2% over 100 cycles in a carbonate electrolyte,
and full cells paired with a high-areal-capacity LiNi0.6Co0.2Mn0.2O2 cathode (3.5 mAh cm–2) exhibit a significantly enhanced cycle lifespan
even under lean electrolyte conditions.