Charge-engineered cellulose nanofibril binders for PFAS-free, high-loading lithium battery positive electrodes

The increasing demand for sustainable high-energy lithium-ion batteries has heightened concerns over the environmental and health impacts of per- and polyfluoroalkyl substances, used in current battery components. In particular, polyvinylidene fluoride, a synthetic resin used as the dominant electrode binder, relies on fluorinated chemicals and toxic solvents such as N-methyl-2-pyrrolidone, while also suffering from limited structural integrity under high-mass-loading conditions. Here, we show that a PFAS- and N-methyl-2-pyrrolidone-free binder based on charge-engineered cellulose nanofibrils derived from natural wood offers a renewable and sustainable alternative to polyvinylidene fluoride. The charge-engineered cellulose nanofibril binder, leveraging its cationic functional groups, promotes particle dispersion in the slurry through electrostatic repulsion and subsequently forms strong …