Sodium‐Ion Hybrid Battery Combining an Anion‐Intercalation Cathode with an Adsorption‐Type Anode for Enhanced Rate and Cycling Performance

Abstract Sodium‐ion batteries (SIBs) are based on natural abundant and low‐cost materials and show a good chemical safety. They have thus become an alternative battery technology to conventional lithium‐ion batteries. However, SIBs usually suffer from poor rate capability and insufficient cycling performance caused by the sluggish reaction kinetics of the large Na + ions, restricting their practical application. Herein, we report a novel sodium‐ion hybrid battery (SHB) combining an anion intercalation‐type graphite cathode material with an adsorption‐type hierarchical porous carbon anode material. The hierarchical porous amorphous carbon is derived from a natural biomass template with macro‐, meso‐, and micro‐ pores as well as high specific surface area, which are beneficial for fast adsorption/desorption of Na + ions. Consequently, attributed from the hybrid battery design, this SHB exhibits excellent rate capability and cycling performance with a reversible capacity of 80 mAh g −1 at 2 C over a voltage window of 0–3.8 V and capacity retention of 87 % after 1000 cycles at 10 C.