Metal dicarboxylates as anode materials for Li-ion batteries

Abstract

Holistic investigations into the various mechanisms of battery electrodes are essential for the development of competitive and sustainable novel battery materials. Specifically, deeper insights into the relationship between the electrode nano and microstructure and electrochemical performance provide avenues for significantly increasing the performance of a material. Here we report the use of novel metal-dicarboxylate metal–organic frameworks made from abundant and inexpensive building blocks as anode materials for Li ion batteries. Additionally, in-depth characterisation of the produced electrodes using X-ray diffraction (XRD), small angle neutron scattering (SANS) and scanning electron microscopy (SEM) showed that the electrode nano and microstructures could be tuned through variations in the electrode formulation. Namely, dissolution of the active materials was found to be greater in water-based slurries as compared to NMP-based slurries. This led to better distribution and dispersion of the active material in the dried electrode, which showed strong correlation with an increase in the specific capacity of the material. In the case of iron(II) tartrate, an improvement of ∼430 mA h g⁻¹ to ∼870 mA h g⁻¹ was recorded. An additional benefit of this formulation approach is the ability to replace toxic NMP-based formulation with benign and green water-based formulation.