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• A novel hydrogen ion supercapattery was assembled. • N and P co-doped carbon paper was effectively acted as the cathode substrate. • The cyclic stability could be improved by modifying the cathode with Nafion. Hydrogen ion battery is a promising energy storage device due to its advantages of non-pollution, excellent rate capability and feasibility at low temperature. Herein, we assemble a novel rechargeable hydrogen ion supercapattery with the iodine-absorbed carbon paper doped with N and P (I 2 -NP-CP) as the cathode electrode and molybdenum trioxide as the anode electrode. Typically, the I 2 -NP-CP electrode shows the superior rate capability from 1 A g−1 (174.7 mAh g−1, 483.8 F g−1) to 20 A g−1 (111.1 mAh g−1, 307.7 F g−1), mainly ascribed to the strong interaction between iodine and the NP-CP substrate. Furthermore, electrochemical measurement of the I 2 -NP-CP@Nafion//MoO 3 supercapattery manifests that the electrodes exhibit excellent cycling stability, retaining 124.3 mAh g−1 after 500 cycles at 15 A g−1, accounting for 93.2 % of the initial capacity. Although some IO 3 − dissolves in the electrolyte due to the weak chemical interaction between IO 3 − and NP-CP, and cannot be completely reduced to I− during discharge process, it can be improved by modification of electrode with Nafion resin to further better the cycling stability. The excellent electrochemical properties in this study show the possibility for the development of novel rechargeable hydrogen ion supercapattery system. [Display omitted] [ABSTRACT FROM AUTHOR]

• The pomegranate-like Si@C microspheres were successfully prepared with inexpensive AlSi alloy by surface modification, coating with resin, carbonization, and acid etching processes. • The distinctive pomegranate-like Si@C structure stabilizes the porous structure of Si particle and improves the electrochemical property. • As high as 84.98% ICE and 100% Coulombic efficiency were obtained for the sample (Si40@C3), which provide a helpful guide to synthesize the Si/C anode with high ICE and Coulombic efficiency and stable cycling. Si/C materials are considered as the most promising anodes for the next generation lithium ion batteries. However, the Si/C anodes with high Coulombic efficiency are still a challenge. Here, pomegranate-like Si@C microspheres are successfully prepared with inexpensive AlSi alloy by surface modification, coating with resin, carbonization and acid etching processes. As high as 84.98% initial Coulombic efficiency (ICE) and 100% Coulombic efficiency are obtained for the sample (Si 40 @C3), and the specific capacity still maintained over 620 mAh g−1 with capacity retention of 70.4% over 250 cycles. The excellent electrochemical performance could be attributed to the distinctive pomegranate-like Si@C structure, which either stabilizes the porous structure of Si particle by inhibiting the volume expansion and pulverization or improves the electrochemical property by the appropriate carbon coating layer. This would provide a helpful guide to synthesize the Si/C anode with high ICE and Coulombic efficiency and stable cycling. [ABSTRACT FROM AUTHOR]