The aqueous ammonium-ion batteries (AAIBs) exhibit significant significance because of their high energy, cost-effectiveness, environmental friendliness, and high safety. Nonetheless, electrode materials with good cycle stability as well as great capacity have a crucial role in developing aqueous ammonium ion batteries. Herein, flower-like CuS microspheres were successfully utilized in AAIBs. The experimental results demonstrated that the as-synthetized copper sulfides revealed high conductivity and flower-like microspheres, and its initial discharge capacity was as high as 710 mAh g−1 at the 0.1 A g−1 current density. Moreover, the cycle stability of batteries were greatly improved by optimizing the electrolyte composition. These results represent a novel design strategy for the AAIBs.