Bismuth nanoparticles@carbon composite as a stable and high capacity anode for high-voltage bismuth-manganese batteries

Bismuth (Bi) electrochemistry holds great potential for aqueous energy storage in terms of its highly-reversible redox capability in alkaline solution, low-cost, and safety. However, Bi-based batteries still suffer from limited performance of Bi anodes and unsatisfying output voltage. Herein, to address these issues, we develop an advanced Bi electrode consisting of oxygen-functionalized Bi nanoparticles embedded in porous carbon frameworks (Bi@C), which was paired with a high potential MnO2 cathode via an electrolyte-decoupling configuration to achieve a high voltage bismuth-based battery. The presence of the subtly-designed oxygen interface favors efficient adsorption of OH- ions while its unique 3D carbon matrix provides an interconnected pathway for electron charge transport. As a result, the Bi@C anode exhibits a remarkable capacity (347.2 mAh g(-1) at 3 A g(-1)) close to its theoretical value, an excellent rate capability (60% capacity retention at a high current density of 20 A g(-1)) and outstanding long-term cyclability (96% capacity retention over 9500 cycles). Furthermore, this new Bi//MnO2 hybrid battery possesses merits of high energy density (213 Wh kg(-1)) and output voltage (1.62 V). This work is expected to shed some lights on properly elevating the energy density of aqueous Bi batteries via electrode design.

Automated summary

The advanced Bi electrode, consisting of oxygen-functionalized Bi nanoparticles embedded in porous carbon frameworks, paired with a high potential MnO2 cathode, achieves high voltage bismuth-based battery with remarkable capacity, excellent rate capability, and outstanding long-term cyclability. This new Bi//MnO2 hybrid battery possesses merits of high energy density and output voltage, showing potential for elevating the energy density of aqueous Bi batteries via electrode design.