Antimony/carbon nanocomposite anode for Na-ion battery shows high capacity and stability

29 May 2012

Researchers at Wuhan University (China) have synthesized a Sb/C (antimony/carbon) nanocomposite for use as an anode material in a room-temperature sodium-ion (Na-ion) battery.

A comparison of the cycling capacities of the metallic Sb and the Sb/C nanocomposite electrode at a current rate of 100 mA/g. Source: Yang et al. Click to enlarge.

The Sb/C nanocomposite delivers a reversible 3 Na storage capacity of 610 mAh/g; a strong rate capability at a very high current of 2000 mA/g and a long-term cycling stability with 94% capacity retention of more than 100 cycles. The material thus could serve as a high capacity and cycling-stable anode for room temperature Na-ion batteries, the researchers suggest in a paper published in the RSC journal Chemical Communications.

To measure the electrochemical performance of the Sb/C nanocomposite, the team used 2032-type coin cells. The working electrode was made by spreading an electrode slurry of 80 wt% active material, 10 wt% CMC binder and 10 wt% Super P on copper foil substrate. A sodium disk served as the counter and reference electrode.

Sodium-ion batteries are considered a potential attractive alternative to lithium-ion batteries, and members of the Wuhan team have worked with the US Pacific Northwest National Laboratory (PNNL) on cathode materials (earlier post). 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 (earlier post).

Resources

• Han Xi Yang, Jiangfeng Qian, Yao Chen, Lin Wu and Yuliang Cao (2012) High Capacity Na-storage and Superior Cyclability of Nanocomposite Sb/C Anode for Na-ion Batteries. Chem. Commun. doi: 10.1039/C2CC32730A