Studies of Lithium-Exchanged Nafion as an Electrode Binder for Alloy Negatives in Lithium-Ion Batteries

The use of lithium-exchanged Nafion as a polymer binder for alloy negative electrodes in lithium-ion batteries is demonstrated. Commercial Nafion solution was ion exchanged with LiOH in order to remove the mobile protons and prepare the lithium-containing polymer. The resulting Li-Nafion solution, crystalline silicon, and carbon black were used to prepare composite electrodes having final proportions of 8% binder, 80% silicon, and 12% carbon by weight, respectively. The prepared electrodes gave reversible specific capacities ranging from 800 to nearly 1000 mAh/g when cycled between 0.9 and 0.17 V. The capacity retention of the investigated electrode samples was very good, suggesting that lithium-exchanged Nafion is a promising binder for alloy negative electrodes of Li-ion batteries.