Tzeng Yonhua, Jhan Cheng-Ying, Chen Guan-Yu, Chiu Kuo-Ming, Wu Yi-Chen, Wang Pin-Sen
Institute of Microelectronics, Department of Electrical Engineering, College of Electrical and Computer Engineering, National Cheng Kung University, Tainan 701, Taiwan.
ACS Omega. 2023 Feb 15;8(8):8001-8010. doi: 10.1021/acsomega.2c07830. eCollection 2023 Feb 28.
A silicon-based lithium-ion battery (LIB) anode is extensively studied because of silicon's abundance, high theoretical specific capacity (4200 mAh/g), and low operating potential versus lithium. Technical barriers to large-scale commercial applications include the low electrical conductivity and up to about 400% volume changes of silicon due to alloying with lithium. Maintaining the physical integrity of individual silicon particles and the anode structure is the top priority. We use strong hydrogen bonds between citric acid (CA) and silicon to firmly coat CA on silicon. Carbonized CA (CCA) enhances electrical conductivity of silicon. Polyacrylic acid (PAA) binder encapsulates silicon flakes by strong bonds formed by abundant COOH functional groups in PAA and on CCA. It results in excellent physical integrity of individual silicon particles and the whole anode. The silicon-based anode shows high initial coulombic efficiency, around 90%, and the capacity retention of 1479 mAh/g after 200 discharge-charge cycles at 1 A/g current. At 4 A/g, the capacity retention of 1053 mAh/g was achieved. A durable high-ICE silicon-based LIB anode capable of high discharge-charge current has been reported.
硅基锂离子电池（LIB）负极受到广泛研究，这是因为硅储量丰富、理论比容量高（4200 mAh/g）且相对于锂的工作电位低。大规模商业应用的技术障碍包括硅的低电导率以及与锂合金化时高达约400%的体积变化。维持单个硅颗粒和负极结构的物理完整性是首要任务。我们利用柠檬酸（CA）与硅之间的强氢键将CA牢固地包覆在硅上。碳化CA（CCA）提高了硅的电导率。聚丙烯酸（PAA）粘结剂通过PAA和CCA中大量COOH官能团形成的强键包裹硅片。这使得单个硅颗粒和整个负极具有出色的物理完整性。该硅基负极显示出较高的初始库仑效率，约为90%，在1 A/g电流下经过200次充放电循环后容量保持率为1479 mAh/g。在4 A/g时，实现了1053 mAh/g的容量保持率。已报道了一种能够承受高充放电电流的耐用高初始库仑效率硅基LIB负极。
