NPG Asia Materials ( IF 9.7 ) Pub Date : 2017-04-14 , DOI: 10.1038/am.2017.51 Patrick Joo Hyun Kim , Jihoon Seo , Kun Fu , Junghyun Choi , Zhiming Liu , Jiseok Kwon , Liangbing Hu , Ungyu Paik
Lithium sulfur (Li-S) batteries have drawn much attention as next-generation batteries because of their high theoretical capacity (1672 mAh g−1), environmental friendliness and low cost. However, several critical issues, which are mainly associated with the polysulfide shuttling effect, result in their poor electrochemical performance. Carbon-modified separators have been introduced to attempt to address these systemic challenges. However, this approach focused only on the suppression of dissolved polysulfides on the cathodic side without considering the further entrapment of polysulfides on the anodic side. In this study, we first designed a multifunctional trilayer membrane comprising a carbon layer and a boron nitride (BN) layer to facilitate the electrochemical performance of Li-S batteries and protect the Li anode from unexpected side reactions. When a BN-carbon separator was employed, the sulfur cathode delivered stable capacity retention over 250 cycles and an excellent specific capacity (702 mAh g−1) at a high current density (4 C). The BN-carbon separator also facilitated the uniform plating/striping of Li and, thus, suppressed the severe growth of dendritic Li on the electrode; this led to the stable operation of the Li anode with a high Coulombic efficiency and improved cycling performance.
中文翻译:
BN-碳隔板对高稳定性锂硫电池的协同保护作用
锂硫(Li-S)电池由于其理论容量高(1672 mAh g -1),环境友好且成本低廉。然而,主要与多硫化物的穿梭效应有关的几个关键问题导致其不良的电化学性能。为了解决这些系统性难题,引入了碳改性隔板。然而,该方法仅集中于抑制在阴极侧上的溶解的多硫化物,而没有考虑在阳极侧上进一步捕获多硫化物。在这项研究中,我们首先设计了一个包含碳层和氮化硼(BN)层的多功能三层膜,以促进Li-S电池的电化学性能并保护Li阳极免受意外副反应的影响。当使用BN碳隔离器时,-1)在高电流密度(4 C)下。BN-碳隔板还促进了Li的均匀镀覆/剥离,因此抑制了电极上的树枝状Li的严重生长。这导致锂阳极以高库仑效率稳定运行并改善了循环性能。