Researchers improve the performance of sodium-ion batteries by using tailored carbon anodes with hierarchical porosity
Researchers at Justus Liebig University, Giessen, Germany, have improved the performance of sodium-ion batteries (earlier post) by using tailor-made carbon materials with hierarchical porosity for the anode instead of common carbon-based anode materials. In a paper published in the RSC journal Energy & Environmental Science, they describe achieving capacities exceeding 100 mA h g−1 at C/5 while exhibiting excellent rate capability and reasonable cycle life.
|Performance of the new anodes. Wenzel et al. Click to enlarge.|
A battery that uses sodium ions instead of lithium ions could potentially be much less expensive and safer, and it would be more environmentally benign. However, Na-ion batteries have exhibited weak charge-discharge behavior except at high temperature—indicative of sluggish kinetics in standard carbon anodes.
Wenzel et al. prepared a carbon material with interconnected pores in two size ranges. Comparison testing with anodes made from a series of commercial porous and reference carbons showed improved charge-storage capacity and recyclability and a 15-fold increase in room-temperature charge-discharge rates with the new material.
Sebastian Wenzel, Takeshi Hara, Jürgen Janek and Philipp Adelhelm (2011) Room-temperature sodium-ion batteries: Improving the rate capability of carbon anode materials by templating strategies. Energy Environ. Sci. Advance Article doi: 10.1039/C1EE01744F
Mitch Jacoby, “Making Better Sodium-Ion Batteries Templated Porous Carbon Electrode Speeds Up Ion Transport”, C&EN, 25 July 2011, Volume 89, Number 30, p. 38