Realization of high mass loading LiNi0.5Mn1.5O4 Li-ion cathodes using water-soluble carrageenan as binder

Cobalt-free LiNi0.5Mn1.5O4 (LNMO) is considered a very promising cathode material candidate for more sustainable lithium-ion batteries, especially when processed into electrodes using water-soluble, fluorine-free binding agents. However, the realization of high-performance electrodes with commercially relevant active material mass loadings remained challenging so far, as such binders are commonly rather brittle and/or suffer from an insufficient electrochemical stability towards oxidation. Herein, we report the use of (citric acid cross-linked) carrageenan as alternative binder for LNMO cathodes, enabling the realization of electrodes with an active material mass loading as high as 20 mg cm−2. These electrodes show suitable mechanical, physicochemical, and electrochemical properties and offer very good cycle life and rate capability in half-cells graphite‖LNMO full-cells with a capacity retention of about 76% after 1000 cycles at 1C. A particular advantage of carrageenan is that it is already available at industrial scale, rendering its practical use rather straightforward.