Effects of Adding HPC to Si-Alloy Anode Slurry of Lithium Secondary Battery

Abstract

This study was carried out to analyze the effects of adding hydroxypropyl cellulose (HPC) on the rheology and dispersibility of the slurry and battery characteristics when fabricating an anode slurry containing Si alloy as the active material, a water-based binder, and deionized water as the solvent. The addition of HPC resulted in a reduction in the viscosity and excellent dispersion in the slurry. In the battery, the adhesiveness of the electrode and current collector was improved, and the initial capacity, polarization resistance, and cycling performance were improved. In addition, the expansion in thickness decreased. This was because HPC suppressed coagulation by steric hindrance and simultaneously acted as a binder by being adsorbed on the particle surfaces of the Si alloy and Ketjen black.

Multidimensional Branched Composite Binder via Covalent Grafting for High-Performance Silicon-Based Anodes

“…This way of the small molecules grafting the polymer does not reduce the overall density of polar groups as does the introduction of large molecules or the formation of cross-linked structures. Moreover, due to the less steric hindrance and multiple polar groups of small molecules (CA), compared to the larger steric hindrance caused by introducing macromolecules, − the CA- g -PAA binder can make more use of PAA-owned polar groups and provide more active sites through covalent bonding with −OH on the surface of Si. The bonding strength is enhanced between Si and the CA- g -PAA binder, thereby mitigating the volume change of Si electrodes, which reduces the isolated active particles formed by shrinkage and maintains the integrity of the electrode.…”