Electroactive materials with high electrochemical activity, good rate capability and excellent cycling stability are urgently needed for hybrid supercapacitors, but achieving those performances at the same time is still a big challenge. Here, α phase nickel−cobalt−manganese hydroxide (NiCoMn−OH) with a flower-like structure is synthesized and used as the battery materials for hybrid supercapacitor. The NiCoMn−OH exhibits strong synergetic electrochemistry between the transition metals, which contributes better charge storage performances. The NiCoMn−OH shows a specific capacity of 757 C g−1 at 1 A g−1 and retains 369 C g−1 at very high specific current of 50 A g−1, which are both much higher than the corresponding bimetal and nomometal hydroxides. Therefore, both high electrochemical activity and rate capability have been achieved. The α phase NiCoMn−OH also exhibits a long-term cycling stability because the specific role of Co, maintaining 100% of the specific capacity after 1200 cycles. The hybrid supercapacitor based on NiCoMn−OH also shows high specific capacity of 219 C g−1 at 1 A g−1, high rate performance of 53% capacity retention when the specific current increases 25 times and ultralong cycling stability of 83% capacity retention after 12,000 cycles.