Yun Jong Hyuk, Moon San, Kim Do Kyung, Kim Joo-Hyung
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.
Advanced Materials Division, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea.
Nanomaterials (Basel). 2021 Nov 13;11(11):3053. doi: 10.3390/nano11113053.
Due to the demand to upgrade from lithium-ion batteries (LIB), sodium-ion batteries (SIB) have been paid considerable attention for their high-energy, cost-effective, and sustainable battery system. Red phosphorus is one of the most promising anode candidates for SIBs, with a high theoretical specific capacity of 2596 mAh g and in the discharge potential range of 0.01-0.8 V; however, it suffers from a low electrical conductivity, a substantial expansion of volume (~300%), and sluggish electron/ion kinetics. Herein, we have designed a well-defined electrode, which consists of red phosphorus, nanowire arrays encapsulated in the vertically aligned carbon nanotubes (P@C NWs), which were fabricated via a two-step, anodized-aluminum oxide template. The designed anode achieved a high specific capacity of 2250 mAh g (87% of the theoretical capacity), and a stepwise analysis of the reaction behavior between sodium and red phosphorus was demonstrated, both of which have not been navigated in previous studies. We believe that our rational design of the red phosphorus electrode elicited the specific reaction mechanism revealed by the charge-discharge profiles, rendered excellent electrical conductivity, and accommodated volume expansion through the effective nano-architecture, thereby suggesting an efficient structure for the phosphorus anode to advance in the future.
由于从锂离子电池（LIB）升级的需求，钠离子电池（SIB）因其高能、经济高效且可持续的电池系统而受到了广泛关注。红磷是钠离子电池最有前景的负极候选材料之一，其理论比容量高达2596 mAh g，放电电位范围为0.01 - 0.8 V；然而，它存在电导率低、体积大幅膨胀（约300%）以及电子/离子动力学迟缓等问题。在此，我们设计了一种结构明确的电极，它由红磷、封装在垂直排列的碳纳米管中的纳米线阵列（P@C NWs）组成，该电极通过两步阳极氧化铝模板法制备而成。所设计的负极实现了2250 mAh g的高比容量（为理论容量的87%），并展示了钠与红磷之间反应行为的逐步分析，这两点在以往的研究中均未涉及。我们认为，我们对红磷电极的合理设计引出了充放电曲线所揭示的特定反应机理，赋予了优异的电导率，并通过有效的纳米结构容纳了体积膨胀，从而为未来磷负极的发展提出了一种高效的结构。
