Nanocasting construction of few-graphene-layers carbon with tunable layer spacing as ultra-stable anode for sodium-ion batteries

Sodium-ion batteries (SIBs) are competitive candidates to the next-generation batteries with respect to the abundant Na resources and potentially low cost. Exploring novel anodes for SIBs is essentially important for their practical application. Here, we successfully constructed few-graphene-layers carbon with controllable layer spacing via a simple nanocasting method, which offered a reproducible model to study the Na+ storage mechanisms in carbon materials. In combination with state-of-the-art characterization technologies involving materials and electrochemistry, interlayer spacing was a critical factor and the one with 0.40 nm exhibited the superior electrochemical performance, e.g. a high reversible capacity of 288 mA h g-1 at 20 mA g-1, rate capacity (120 mA h g-1 at 5 A g-1), an excellent capacity retention (barely loss; -200 mA h g-1 after 1000 cycles at 100 mA g-1). This study correlated the microstructure of carbon materials with electrochemical performance and provided a design principle for carbon-based anodes for SIBs.

Automated summary

Researchers successfully constructed few-graphene-layers carbon and explored its electrochemical performance in sodium-ion batteries. The study showed that interlayer spacing is a critical factor affecting the performance, with a spacing of 0.40 nm exhibiting superior performance.