A comprehensive study of hydrolyzed polyacrylamide as a binder for silicon anodes

Silicon anodes have a high theoretical capacity for lithium storage, but current composite electrode formulations are not sufficiently stable under long–term electrochemical cycling. The choice of polymeric binder has been shown to impact stability and capacity of silicon anodes for electrochemical energy storage. While several promising polymeric binders have been identified, there is a knowledge gap in how various physico–chemical properties – including adhesion, mechanical integrity and ion diffusion – impact electrochemical stability and performance. In this work, we comprehensively investigate the physical properties and performance of a molecular–weight series (3 – 20 × 10 6 g/mol) of partially–hydrolyzed polyacrylamide (HPAM) in silicon anodes. We quantify the mechanical strength, electrolyte uptake, adhesion to silicon, copper and carbon, as well as electrochemical performance and stability and find that HPAM satisfies many of the properties generally believed to be favorable, including good adhes...