Efficient conducting networks constructed from ultra-low concentration carbon nanotube suspension for Li ion battery cathodes

Carbon nanotubes (CNTs) with large length-diameter ratios and high conductivity are ideal to fabricate conductive networks in cathodes for Li ion batteries. However, good dispersion of CNTs in cathodes remains great challenge. Here, a CNT suspension containing an ultra-low concentration (0.2 wt%) of vertically-aligned CNTs (VACNTs) is used to construct a well-dispersed conductive network in cathodes. The VACNTs exhibit excellent dispersion stability in N-methyl pyrrolidone due to less entangling between CNTs. Significant promotion in specific capacities and low temperature performance have been achieved by adding highly-dispersed VACNTs into LiFePO4 cathodes.