Hard Carbon Anodes for Na-Ion Batteries: Toward a Practical Use
Hard Carbon Anodes for Na-Ion Batteries: Toward a Practical Use
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DOI：
10.1002/celc.201500412
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发表时间：
2015-12
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通讯作者：
George Hasegawa;K. Kanamori;Naokatsu Kannari;J. Ozaki;K. Nakanishi;T. Abe
中科院分区：
文献类型：
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作者：
George Hasegawa;K. Kanamori;Naokatsu Kannari;J. Ozaki;K. Nakanishi;T. Abe
硬碳作为钠离子电池的阳极材料具有巨大的潜力，因为膨胀的石墨烯夹层和随机堆叠的芳族片段之间的纳米空隙可以容纳大量的钠。然而，第一循环中的大的不可逆容量仍然是实用电池技术方面的重要问题。在这里，我们表明，从一个共同的酚醛树脂衍生的硬碳电极提供了高可逆容量在0.1-0.005 V（相对于Na+/Na）的窄电位范围内和一个优秀的初始库仑效率高达95%。前者允许可持续的高电压，而后者使封闭电池中不可用的Na+的量最小化。这项工作的结果提出了一个指导方针，制造硬碳电极，这违背了目前的趋势，纳米结构化和小型化。
Hard carbons have immense potential as anode materials for Na-ion batteries, because the expanded graphene interlayers and nanovoids between randomly stacked aromatic fragments can accommodate a substantial amount of sodium. However, the large irreversible capacity in the first cycle still remains as a significant issue in terms of a practicable battery technology. Here, we show that hard carbon electrodes derived from a common phenol resin deliver a high reversible capacity within the narrow potential range of 0.1–0.005 V (vs. Na+/Na) and an excellent initial coulombic efficiency up to 95 %. The former allows the sustainable high voltage, whereas the latter minimizes the amount of unavailable Na+ in a closed cell. The findings in this work put forward a guideline for manufacturing hard carbon electrodes, which goes against the current trend of nanostructuring and downsizing.