Kim Kangmin, Bon Chris Yeajoon, Kim Junghyun, Ko Jang Myoun, Choi Wonseok
Department of Electrical Engineering, Hanbat National University, Daejeon 34158, Republic of Korea.
Department of Materials Science and Engineering, Research Institute of Advanced Materials (RIAM), Seoul National University, Seoul 08826, Republic of Korea.
Nanomaterials (Basel). 2023 Sep 22;13(19):2622. doi: 10.3390/nano13192622.
In this paper, a new synthesis of carbon nanofibers (CNFs)/carbon nanowalls (CNWs) was performed to improve the characteristics of anode materials of lithium-ion batteries by using the advantages offered by CNWs and CNFs. Among the carbon-based nanomaterials, CNWs provide low resistance and high specific surface area. CNFs have the advantage of being stretchable and durable. The CNWs were grown using a microwave plasma-enhanced chemical vapor deposition (PECVD) system with a mixture of methane (CH) and hydrogen (H) gases. Polyacrylonitrile (PAN) and N,N-Dimethyl Formamide (DMF) were stirred to prepare a solution and then nanofibers were fabricated using an electrospinning method. Heat treatment in air was then performed using a hot plate for stabilization. In addition, heat treatment was performed at 800 °C for 2 h using rapid thermal annealing (RTA) to produce CNFs. A field emission scanning electron microscope (FE-SEM) was used to confirm surface and cross-sectional images of the CNFs/CNWs anode materials. Raman spectroscopy was used to examine structural characteristics and defects. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and constant current charge/discharge tests were performed to analyze the electrical characteristics. The synthesized CNFs/CNWs anode material had a CV value in which oxidation and reduction reactions were easily performed, and a low Rct value of 93 Ω was confirmed.
在本文中，利用碳纳米壁（CNWs）和碳纳米纤维（CNFs）的优势，对锂离子电池负极材料的特性进行了新型碳纳米纤维/碳纳米壁的合成。在碳基纳米材料中，CNWs具有低电阻和高比表面积的特点。CNFs具有可拉伸和耐用的优势。使用微波等离子体增强化学气相沉积（PECVD）系统，以甲烷（CH）和氢气（H）的混合气体生长CNWs。将聚丙烯腈（PAN）和N，N-二甲基甲酰胺（DMF）搅拌制成溶液，然后采用静电纺丝法制备纳米纤维。然后使用热板在空气中进行热处理以实现稳定化。此外，使用快速热退火（RTA）在800℃下进行2小时的热处理以制备CNFs。用场发射扫描电子显微镜（FE-SEM）确认CNFs/CNWs负极材料的表面和横截面图像。使用拉曼光谱检查结构特征和缺陷。进行循环伏安法（CV）、电化学阻抗谱（EIS）和恒流充/放电测试以分析电学特性。合成的CNFs/CNWs负极材料具有易于进行氧化和还原反应的CV值，并且确认其Rct值低至93Ω。
