Towards eco-friendly batteries: high temperature baking of carbonaceous (MCMB) Li-ion anodes containing advanced water-based natural polymer binders results in superior performance

Replacing common polymeric binder materials in lithium-ion batteries (LIBs) with more sustainable and environmentally friendly options is one of the challenges in designing new generations of LIBs. Here, we explain how incorporating protein-based polymers into the binder formulation can enhance binder performance in the graphite anode of LIBs. The electrode preparation with these binders involves an atypical thermal treatment (“baking”) that causes structural transformation. The effect of baking temperature on battery performance is examined using various methods covering morphological, structural, and electrochemical aspects. We find that baking the binders at temperatures above 120 °C removes tightly bound water molecules, which impair LIB performance. Water removal promotes intra- and inter-molecular bond formation among the binder components, while the primary covalent structure of these binders remains unchanged. Ultimately, using thermally treated binders enhances the electrochemical performance of graphite anodes and provides strong adhesion. The ideas presented here could significantly influence the design of new binders for LIBs.