Exceptional energy and new insight with a sodium-selenium battery based on a carbon nanosheet cathode and a pseudographite anode
Exceptional energy and new insight with a sodium-selenium battery based on a carbon nanosheet cathode and a pseudographite anode
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DOI：
10.1039/c6ee02274j
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发表时间：
2017-01-01
影响因子：
32.5
通讯作者：
Mitlin, David
中科院分区：
文献类型：
--
作者：
Ding, Jia;Zhou, Hui;Mitlin, David
我们创建了一种独特的钠离子电池（NIB，SIB）阴极，该阴极基于纤维素衍生的碳纳米片（CCN）中的硒，称为Se-CCN。弹性顺应性二维CCN主体结合了高质量负载的无定形Se（53重量%），其主要浸渍到1 cm（3）g（-1）纳米孔中。结果在轻便钠化动力学由于短的固态扩散距离和大的电荷转移面积的纳米片建立。该结构还导致对多硒化物穿梭和崩解/粗化的固有抗性。作为Na半电池，Se-CCN阴极在500次循环中提供613 mA h g（-1）的可逆容量，具有88%的保留率。通过使用标准电解质（1 M NaClO 4 EC-DMC）实现卓越的稳定性，无需二次添加剂或高盐浓度。速率能力也是一流的，达到300 mA h g（-1）在10 C。与最近的最先进的文献相比，Se-CCN是最周期稳定的，并提供最高的速率性能。作为Se-Na电池，该系统在68 W kg（-1）下达到992 W h kg（-1），在10 144 W kg（-1）下达到384 W h kg（-1）（按阴极中的活性质量计）。我们是第一家制造和测试基于Se的全NIB的公司，该NIB基于Se-CCN耦合到Na嵌入伪石墨碳（PGC）阳极。它表明，PGC阳极增加其结构顺序，除了膨胀作为Na嵌入在电压低于0.2 V相对于Na/ Na+的结果。钠化低至0.001 V的PGC的XRD图案中明显不存在{110} Na反射，表明Na金属孔填充对于假石墨碳不显著。该电池提供了非常有前途的Ragone图表特性，例如在70和14 000 W kg（-1）下产生203和50 W h kg（-1）（通过阳极和阴极中的总材料质量）。
We created a unique sodium ion battery (NIB, SIB) cathode based on selenium in cellulose-derived carbon nanosheets (CCNs), termed Se-CCN. The elastically compliant two-dimensional CCN host incorporates a high mass loading of amorphous Se (53 wt%), which is primarily impregnated into 1 cm(3) g(-1) nanopores. The results in facile sodiation kinetics due to short solid-state diffusion distances and a large charge transfer area of the nanosheets were established. The architecture also leads to an intrinsic resistance to polyselenide shuttle and to disintegration/ coarsening. As a Na half-cell, the Se-CCN cathode delivers a reversible capacity of 613 mA h g(-1) with 88% retention over 500 cycles. The exceptional stability is achieved by using a standard electrolyte (1 M NaClO4 EC-DMC) without secondary additives or high salt concentrations. The rate capability is also superb, achieving 300 mA h g(-1) at 10C. Compared to recent state-of-the-art literature, the Se-CCN is the most cyclically stable and offers the highest rate performance. As a Se-Na battery, the system achieves 992 W h kg(-1) at 68 W kg(-1) and 384 W h kg(-1) at 10 144 W kg(-1) (by active mass in a cathode). We are the first to fabricate and test a Se-based full NIB, which is based on Se-CCN coupled to a Na intercalating pseudographitic carbon (PGC) anode. It is demonstrated that the PGC anode increases its structural order in addition to dilating as a result of Na intercalation at voltages below 0.2 V vs. Na/ Na+. The {110} Na reflections are distinctly absent from the XRD patterns of PGC sodiated down to 0.001 V, indicating that the Na metal pore filling is not significant for pseudographitic carbons. The battery delivers highly promising Ragone chart characteristics, for example yielding 203 and 50 W h kg(-1) at 70 and 14 000 W kg(-1) (via total material mass in the anode and cathode).