In contemporary years, the increasing demand for high-capacity and safe energy storage has spurred wide attentions in zinc batteries featuring either high voltage, high capacity or both. Despite the extensive research progress, achieving high-energy-density zinc batteries is still challenging and requires a synergy of the multiple factors including reaction mechanisms, electrodes, and electrolytes. In this Review, we comprehensively summarize the rational design strategies, and critically analyze the positive effects and potential issues in optimizing the electrochemistry, cathode materials, electrolytes and device architecture. At the end, the challenges and prospects for the further development of high-energy-density zinc batteries are outlined to guide the research towards new-generation batteries for household appliance, low-speed electric vehicles and large-scale energy storage system.