Deng Li, Deng Sai-Sai, Pan Si-Yu, Wu Zhan-Yu, Hu Yi-Yang, Li Kai, Zhou Yao, Li Jun-Tao, Huang Ling, Sun Shi-Gang
College of Energy, Xiamen University, Xiamen 361005, China.
Laboratoire de Physico-Chimie des Surfaces, Chimie-ParisTech-CNRS (UMR 8247), Ecole Nationale Supérieure de Chimie de Paris, 11 rue Pierre et Marie Curie, 75005 Paris, France.
ACS Appl Mater Interfaces. 2021 May 19;13(19):22567-22576. doi: 10.1021/acsami.1c04501. Epub 2021 May 4.
A supramolecular polymer, poly(-acryloyl glycinamide) (PNAGA), with a bisamide group on each side of the chain forming multiple amide-hydrogen bonds was synthesized in this work as a binder for silicon (Si)-based anodes. This supramolecular polymer binder with improved mechanical properties presents good interfacial adhesion with Si particles forming hydrogen bonds and enhances the adhesive strength between the electrode material film and the copper current collector. Benefiting from the highly stable inter- and intramolecular multiple amide-hydrogen bonds of the PNAGA binder, the electrode structure maintains integrity and a stable solid electrolyte interphase (SEI) layer is formed on the surface of Si particles. The effect of different binders on the composition of the SEI film was also investigated by X-photoelectron spectroscopy (XPS) characterization. In comparison with polyacrylamide (PAM), which has a similar structure to PNAGA, and the traditional sodium alginate (SA) binder, the Si electrode containing the PNAGA binder shows improved electrochemical performance. The capacity retention is 84% after 100 cycles at 420 mA g, and the capacity remains at 1942.6 mAh g after 400 cycles at 1260 mA g. Even with a mass loading of 1.2 mg cm Si, the electrode with the PNAGA binder exhibits high initial areal capacity (2.64 mAh cm) and good cycling performance (81% capacity retention after 50 cycles). Moreover, the application of the PNAGA binder also brings a stable cycle performance to the commercial Si-graphite (SiC) anode material.
在本工作中合成了一种超分子聚合物聚（丙烯酰甘氨酰胺）（PNAGA），其链的每一侧都有双酰胺基团，可形成多个酰胺 - 氢键，用作硅（Si）基负极的粘结剂。这种具有改善机械性能的超分子聚合物粘结剂与Si颗粒形成氢键，表现出良好的界面粘附性，并增强了电极材料膜与铜集流体之间的粘结强度。受益于PNAGA粘结剂高度稳定的分子间和分子内多个酰胺 - 氢键，电极结构保持完整，并且在Si颗粒表面形成了稳定的固体电解质界面（SEI）层。还通过X射线光电子能谱（XPS）表征研究了不同粘结剂对SEI膜组成的影响。与结构与PNAGA相似的聚丙烯酰胺（PAM）以及传统的海藻酸钠（SA）粘结剂相比，含PNAGA粘结剂的Si电极表现出改善的电化学性能。在420 mA g下循环100次后容量保持率为84％，在1260 mA g下循环400次后容量保持在1942.6 mAh g。即使Si的质量负载为1.2 mg cm，含PNAGA粘结剂的电极仍表现出高的初始面积容量（2.64 mAh cm）和良好的循环性能（50次循环后容量保持率为81％）。此外，PNAGA粘结剂的应用也为商用硅 - 石墨（SiC）负极材料带来了稳定的循环性能。
