High-Rate and Long-Life Intermediate-Temperature Na-NiCl2 Battery with Dual-Functional Ni-Carbon Composite Nanofiber Network
High-Rate and Long-Life Intermediate-Temperature Na-NiCl2 Battery with Dual-Functional Ni-Carbon Composite Nanofiber Network
复制标题
具有双功能镍碳复合纳米纤维网络的高倍率、长寿命中温Na-NiCl2电池
DOI：
10.1021/acsami.0c04470
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发表时间：
2020-06-03
影响因子：
9.5
通讯作者：
Wen, Zhaoyin
中科院分区：
文献类型：
--
作者：
Gao, Xingpeng;Hu, Yingying;Wen, Zhaoyin
中温钠-金属卤化物(Na-MH)电池迫切需要提高功率和循环性能。低电导率NiCl2层的存在以及镍和氯化钠颗粒的长大限制了Na-NiCl2电池的广泛应用。本文采用多溶液电纺法制备了镍碳复合纳米纤维(NCCN)网络，构建了一种新型的Na-NiCl2电池三维正极材料。以NCCN为正极的电池在190℃下的倍率和循环性能有了显著的提高，在57 mAg(-1)的电流下，100次循环后的容量是传统电极的两倍，400次循环后的容量是初始容量的80%。NCCN基阴极在338 mA g(-1)的大电流下正常工作350次以上，没有明显的退化，也就是2℃的速率。此外，原位电化学阻抗谱准确地揭示了NCCN基正极充放电过程中更快的电子和离子传输过程。研究发现，NCCNs不仅可以起到连续导电网络的作用，而且还可以限制颗粒的生长。在碳纤维的阻挡作用下，镍和氯化钠颗粒的体积膨胀得到很好的抑制，经50次循环后，其尺寸分别小于500 nm和7µm。
Improved power and cycle performances are eagerly required in intermediate-temperature sodium-metal halide (Na-MH) batteries. The existence of the low conductivity NiCl2 layer and the growth of the Ni and the NaCl particles limit the broader application of Na-NiCl2 battery. Herein, nickel-carbon composite nanofiber (NCCN) networks are synthesized by a multisolution electrospinning method to construct a novel three-dimensional cathode for Na-NiCl2 battery. The battery with the NCCN-based cathode shows significant improvement in rate and cycle performance at 190 degrees C. A capacity twice that of a conventional electrode after 100 cycles and 80% of the initial capacity after 400 cycles are observed at a current of 57 mA g(-1). The NCCN-based cathode normally works more than 350 cycles without obvious degradation at a high current of 338 mA g(-1), that is, a rate of 2C. Furthermore, in situ electrochemical impedance spectroscopy reveals faster electron and ion transport processes precisely on the charging and discharging processes of the NCCN-based cathode. It is found that the NCCNs can not only play the role of a continuous conductivity network but also limit the growth of grains. With the blocking effect of the carbon fibers, the volume expansions of Ni and NaCl grains are well restricted and their sizes were smaller than 500 nm and 7 mu m after 50 cycles, respectively.