Energy storage based on sodium ions is considered to be one of the most promising candidates for large-scale applications. However, designing nanostructured anodes with ultralong cycle life, superior rate capability, and high specific capacitance is still a challenge. Herein, we report that nitrogen functionalized carbon nanocages with optimized structures as anodes in sodium-ion half cells demonstrate a superior capacity of 402 mA h g(-1) at 50 mA g(-1), excellent rate performance with 101 mA h g(-1) at 10 A g(-1), and an ultra-long cycle life by retaining 81% of its initial capacity after 5000 cycles at 10 A g(-1). It can be observed that carbons with high nitrogen doping level and few-layer graphene domains are proved to be effective for sodium ion storage. Benefiting from the merits of structure and electrochemical performance of nitrogen functionalized carbon nanocages, the sodium-ion capacitors by using identical carbon electrodes achieves a high energy density of 102.5 W h kg(-1) and an outstanding cycle life of 100,000 cycles with 74.2% of the capacity retention. This work opens a new opportunity for designing high-performance carbon electrodes with scalable production for next-generation energy storage. (C) 2019 Elsevier Ltd. All rights reserved.