Silver niobate AgNbO₃ ceramics have been regarded as a promising lead-free material for energy storage applications. In present work, pure and fine AgNbO₃ powders were successfully fabricated via the hydrothermal method using AgNO₃ as the raw material. It is found that the reaction products show strong dependence on the molar ratio of NH₄HF₂:AgNO₃:Nb₂O₅, pH value and reaction time. Pure AgNbO₃ powders were obtained when the process conditions are 3NH₄HF₂:2AgNO₃:xNb₂O₅ with x≤0.85 or yNH₄HF₂:2AgNO₃:1Nb₂O₅ with y = 4–5, pH = 5 and reaction time t ≥ 10 h. Benefitting from the hydrothermal synthesised AgNbO₃ powders, AgNbO₃ ceramics with fine-grain of ∼3.4 μm were obtained. The fine-grain leads to increased electric breakdown strength E_b up to 250 kV/cm, which is the highest among the pure AgNbO₃ ceramics to our best knowledge. The further enhancement in E_b and recoverable energy density could be highly anticipated if the antiferroelectric phase could be stabilized.

铌酸银AgNbO ₃陶瓷被认为是用于储能应用的有前途的无铅材料。在目前的工作中，以AgNO ₃为原料，通过水热法成功地制备了纯的和细的AgNbO ₃粉末。发现反应产物显示出对NH ₄ HF ₂ ∶AgNO ₃ ∶Nb ₂ O ₅的摩尔比，pH值和反应时间的强烈依赖性。当工艺条件为3NH ₄ HF ₂：2AgNO ₃：x Nb ₂ O时，获得纯的AgNbO ₃粉末。₅与X ≤0.85或ÿ NH ₄ HF ₂：2AgNO ₃：1NB ₂ ö ₅与ÿ = 4-5，pH值= 5和反应时间t≥10小时。得益于水热合成的AgNbO ₃粉末，获得了晶粒细度约为3.4μm的AgNbO ₃陶瓷。细晶粒可将击穿强度E _b提高至250 kV / cm，据我们所知，这在纯AgNbO ₃陶瓷中是最高的。E _b的进一步增强 如果反铁电相可以稳定，那么可回收的能量密度将非常可观。