Formulation and mechanism of copper tartrate – a novel anode material for lithium-ion batteries

Abstract

Batteries play an increasingly critical role in the functioning of contemporary society. To ensure future proofing of battery technology, new materials and methods that overcome the current shortcomings need to be developed. Here we report the use of the inexpensive and off the shelf metal–carboxylate, copper tartrate, as a high-capacity anode material for lithium-ion batteries, providing a specific capacity of 744 mA h g⁻¹ when cycled at 50 mA g⁻¹. Additionally, an unusual capacity gain with cycling is investigated using advanced techniques including X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), and small and ultra-small angle neutron scattering (SANS and USANS), providing insight into the structure–performance relationship of the electrode. Subsequently, a novel method of in situ generation of the active material is demonstrated using the reaction between the parent acid, tartaric acid, and the copper current collector during electrode formulation. This serves to increase and stabilise the electrode performance, as well as to make use of a cheaper feedstock (tartaric acid), and reduce some of the “dead mass” of the copper current collector.