A binary carbon-free aluminum anode for lithium-ion batteries

Modern applications require high energy density lithium-ion batteries (LIBs), inciting the search for high capacity anode materials. Recently, Aluminum (Al) anodes have reemerged as Li-alloyed anode material, but so far have not presented sufficient performance with commercially acceptable mass loadings. Interestingly, the active material intrinsic conductivity is not fully exploited in the design of Al anodes, as traditional powder-based electrodes still rely on carbonaceous additives to improve the conductivity. Herein, we provide a proof-of-principle for the design of a binary carbon-free Al/binder electrode, targeting high areal capacities for the powder-based anode with increased active material content. The simple binary electrode concept has been proven feasible as anodes, producing reversible capacities of about 3 mAh cm⁻², higher than many similar carbon-based systems. By eliminating the conductive additives, the electrode advantaged from high active material loading, and from the mitigation of surface-related side reactions. The binary system behavior was more stable in prolonged cycling, demonstrating that any beneficial role of the carbon in maintaining the electrical conductivity and diminishing Al pulverization is only temporary. The insights on the high loading Al/binder anode provide first guidelines for future high-energy density LIBs via implementation of state-of-the-art architectures in binary Al-based anodes.