Poly(arylene ether sulfone)-derived single-ion conducting (SIC) block copolymers are promising candidates for lithium-metal battery electrolytes owing to their high electrochemical stability and structural versatility. When incorporating small organic molecules (e.g., organic carbonates such as ethylene carbonate, EC) high ionic conductivities can be reached, even at ambient temperatures. To gain further insights into the impact of the polymer backbone chemistry on the physicochemical and electrochemical properties, a series of SIC multi-block copolymers was synthesized comprising bisphenol-derived monomers for the ionophilic block. All of these ionomers (containing 55% of EC) show high ionic conductivities. Remarkably, though, the electrochemical stability towards oxidation is slightly decreasing for an increasing size of the substituent at the central carbon atom of the bisphenol monomer, while the overpotential for the lithium stripping and plating is decreasing. These results highlight the importance of carefully designing the polymer backbone for high-performance lithium battery electrolytes.