Slope‐Dominated Carbon Anode with High Specific Capacity and Superior Rate Capability for High Safety Na‐Ion Batteries

Positive energy: The slope‐dominated carbon anode produced by the inverse low‐temperature strategy shows great potential for low‐cost and high‐safety Na‐ion batteries in terms of high specific capacity, impressive ICE, superior rate capability, and long cycle stability, without any doping, nano‐sizing, or pore‐creating procedures.

Abstract

The comprehensive performance of carbon anodes for Na‐ion batteries (NIBs) is largely restricted by their inferior rate capability and safety issues. Herein, a slope‐dominated carbon anode is achieved at a low temperature of 800 °C, which delivers a high reversible capacity of 263 mA h g⁻¹ at 0.15C with an impressive initial Coulombic efficiency (ICE) of 80 %. When paired with the NaNi_1/3Fe_1/3Mn_1/3O₂ cathode, the reversible capacity at 6C is still 75 % of that at 0.15C, and 73 % of the capacity is retained after 1000 cycles at 3C. The enhanced Na storage performance could be attributed to the unique microstructure with randomly oriented short carbon layers and the relatively higher defect concentration. Given its robustness, such a low‐temperature carbonization strategy could also be applicable to other precursors and provide a new opportunity to design slope‐dominated carbon anodes for high safety, low‐cost NIBs with excellent ICE and superior rate capability.

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