Breakthrough in Sodium-Ion Battery Technology: Unmodified Hard Carbon Anode with High Capacity of 422 mAh/g and Energy Density Unveiled

Date: 16-02-2024

Researchers from the Indian Institute of Technology Kharagpur have achieved a significant breakthrough in sodium-ion battery technology with their work published in the prestigious international blind peer-reviewed journal Chemical Communication by The Royal Society of Chemistry. The study introduces micro-spherical hard carbons (MSHCs) with distinctive porosity features, synthesized through an innovative microwave-assisted solvothermal pre-treatment of sucrose, followed by carbonization. These MSHCs exhibit exceptional properties, including large interlayer spacing of turbostratic graphene nanosheets, hierarchical pore structures, and closed pores, resulting in outstanding performance as anodes for sodium-ion batteries. With a high reversible capacity of 422 mA h/g at a 0.1C rate and outstanding capacity retention of 84% after 500 cycles at 1C, the MSHC sets a new standard for sodium storage performance. Further analyses reveal a mechanism shift from intercalation to quasi-metallic sodium clusters in the closed pores at low potentials, confirmed by GITT and EPR measurements. When paired with a P2-Na0.67Ni0.33Mn0.67O2 (NNMO) cathode, the MSHC anode enables a full cell to achieve a high energy density of 292 W h/kg at a working potential of 3.2 V, showcasing its potential for advancing energy storage technologies.

Authors: Nagmani, S Manna and Sreeraj Puravankara

Read this article: https://doi.org/10.1039/D4CC00025K