Aqueous sodium alginate as binder: Dramatically improving the performance of dilithium terephthalate-based organic lithium ion batteries

Abstract

The electrochemical performance of a typical carbonyl-based organic electrode material dilithium terephthalate is improved remarkably by using sodium alginate as an aqueous binder. Compared to the conventional poly (vinylidene fluoride) binder, the electrode with sodium alginate as a binder shows significant improvement in electrochemical performance. It delivers a high capacity of 200 mAh g−1 after 100 cycles at 0.1C. Even at 1C, it still remains a capacity of 130 mAh g−1 after 1000 cycles with approximately 100% Coulombic efficiency. Due to its high water solubility, dilithium terephthalate distributes uniformly and is surrounded well by electron conductive carbon in the organic electrode with sodium alginate as aqueous binder. The excellent electrochemical performances result from the faster electron transfer, less interfacial impedance and lower polarization of the organic electrode, because the carboxyl and hydroxyl rich groups of sodium alginate facilitate the ion-transporting in the electrode. This work can provide an approach to enhance the performance of not only organic dilithium terephthalate anode, but also other organic electrode materials in various battery systems.