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. (C) 2015 The Electrochemical Society. All rights reserved.