Coulombic efficiency and capacity retention are some of the main issues with alloy anodes in lithium-ion batteries, and the use of electrolyte additives is a viable approach to overcome these problems. Accordingly, the effects of three electrolyte additives, viz., vinylene carbonate (VC), fluoroethylene carbonate (FEC), and vinylethylene carbonate (VEC), on the performance of a promising alloy anode material Cu2Sb–Al2O3–C have been investigated. With an aim to rapidly assess the effects of the electrolyte additives, symmetric cells fabricated with Cu2Sb–Al2O3–C were used. Symmetric cell testing showed results similar to those of conventional half-cell testing in as little as one-fifth of the time, illustrating that symmetric cell testing is a valuable tool for optimization the performance of battery materials. Among the various additives and concentrations investigated, 2% VEC was found to offer the best cell performance with the Cu2Sb–Al2O3–C nanocomposite anode.