Lithium Salt of Tetrahydroxybenzoquinone: Toward the Development of a Sustainable Li-Ion Battery

The use of lithiated redox organic molecules containing electrochemically active C=O functionalities, such as lithiated oxocarbon salts, is proposed. These represent alternative electrode materials to those used in current Li-ion battery technology that can be synthesized from renewable starting materials. The key material is the tetralithium salt of tetrahydroxybenzoquinone (Li4C6O6), which can be both reduced to Li2C6O6 and oxidized to Li6C6O6. In addition to being directly synthesized from tetrahydroxybenzoquinone by neutralization at room temperature, we demonstrate that this salt can readily be formed by the thermal disproportionation of Li2C6O6 (dilithium rhodizonate phase) under an inert atmosphere. The Li4C6O6 compound shows good electrochemical performance vs Li with a sustained reversibility of similar to 200 mAh g(-1) at an average potential of 1.8 V, allowing a Li-ion battery that cycles between Li2C6O6 and Li6C6O6 to be constructed.