An Ultra-Stable, High-Energy and Wide-Temperature-Range Aqueous Alkaline Sodium-Ion Battery with the Microporous C4N/rGO Anode

Abstract Common anode materials in aqueous alkaline electrolytes, such as cadmium, metal hydrides and zinc, usually suffer from remarkable biotoxicity, high cost, and serious side reactions. To overcome these problems, we develop a conjugated porous polymer (CPP) in-situ grown on reduced graphene oxide (rGO) and Ketjen black (KB), noted as C 4 N/rGO and C 4 N/KB respectively, as the alternative anodes. The results show that C 4 N/rGO electrode delivers a low redox potential (−0.905 V vs. Ag/AgCl), high specific capacity (268.8 mAh g −1 at 0.2 A g −1 ), ultra-stable and fast sodium ion storage behavior (216 mAh g −1 at 20 A g −1 ) in 2 M NaOH electrolyte. The assembled C 4 N/rGO//Ni(OH) 2 full battery can cycle stably more than 38,000 cycles. Furthermore, by adding a small amount of antifreeze additive dimethyl sulfoxide (DMSO) to adjust the hydrogen bonding network, the low-temperature performance of the electrolyte (0.1 DMSO/2 M NaOH) is significantly improved while hydrogen evolution is inhibited. Consequently, the C 4 N/rGO//Ni(OH) 2 full cell exhibits an energy density of 147.3 Wh Kg −1 and ultra-high cycling stability over a wide temperature range from −70 to 45 °C. This work provides an ultra-stable high-capacity CPP-based anode and antifreeze electrolyte for aqueous alkaline batteries and will facilitate their practical applications under extreme conditions.