The electrical energy storage system has attracted more and more attentions today because it provides a variety of application solutions in power system, including renewable energy integration, peak shaving/ load leveling, distribution system support, etc. Over the years, many storage technologies have been investigated and developed; some have reached the demonstration level and become commercially available while some are still under research and developing. Among all the emerging technologies, flow batteries distinguish themselves as excellent candidates for large stationary storage applications, for their simplicity, high flexibility in design and competitively long life cycles. Recently, a novel redox zinc-nickel flow battery system with single flow channel was proposed and gained much research interest. Such battery possesses several advantages including the use of cheap and abundant materials, relatively low levels of toxicity and high levels of safety. More importantly, it has no requirement for the expensive ion exchange membranes like other two-channel flow batteries do, so its cost reduces significantly. Compared with other advanced batteries, the new battery system provides a cost-effective solution for energy storage system. Electrolyte flowrate certainly is one of the key factors that determine the performance of a single flow zinc-nickel battery. On one hand, flowing electrolyte inside the battery would change the mass transport of zincate from diffusion control to convection control, thus the thickness of diffusion layer can be reduced distinctly and zinc deposition would become more uniform and flat. Internal short-circuit caused by dendritic deposition used to be the main restriction in life cycle of traditional zinc-nickel battery, and it can be practically avoided by making the electrolyte flowing. But on the other hand, the accessional pump consumed power would cause significant power losses in providing stable and sufficient flow inside the battery stack. So far, the influence of flowrate on overall battery performance regarding to the efficiency losses issue has not been thoroughly studied yet. Therefore, to improve the effects of electrolyte flowrate on overall battery performance, an electrical model for single flow zinc-nickel battery is proposed and studied. The model consists of both battery stack part and pump power part, which consequently not only predicts accurately the battery electrical output, but also estimates the pump consumed power at different electrolyte flowrate. Based on such a model, the influence of flowrate overall system efficiency is further investigated and discussed. It's discovered that compared with fixed flowrate without any control, the adaptive flowrate control would significantly improve the overall system efficiency for single flow zinc-nickel battery. Indeed, there exists an optimal flowrate at each operating current rate according to the limiting current theory. A practical flowrate control method is then proposed. By altering the flowrate at different charge current, the battery performance can be greatly enhanced. The theoretical analyses, as well as both of simulation and experiment results prove that such control method is quite feasible for future applications of single flow zinc-nickel battery.