The improved discharge performance of Li/CFx batteries by using multi-walled carbon nanotubes as conductive additive

The discharge performance of Li/CFx (x = 1) battery is improved by using multi-walled carbon nanotubes (MWCNTs) as an alternative conductive additive. Compared with the battery using acetylene black as conductive additive at the same amount, the Li/CFx battery using MWCNTs as conductive additive has higher specific capacity and energy density as well as smoother voltage plateau, especially at higher discharge rate. The specific capacity at discharge rate of 1 C is improved by nearly 26% when MWCNTs are employed as conductive additive. Meanwhile, it is also found that the discharge performance is able to be tuned by the amount of MWCNTs and the battery containing more MWCNTs is favorable to be discharged at higher rates. The specific capacity of Li/CFx battery with 11.09 wt.% MWCNTs is approximately 712 mAh g−1 at the discharge rate of 1 C. It is proposed that the formed three-dimensional networks of MWCNTs in cathode, which enlarges the contact area of interphase and facilitates electrons delivery, accelerates the rates of lithium ion diffusion into the fluorinated layers and electrons transport in cathode at the same time, which improves the discharge performance of Li/CFx battery subsequently, especially at higher rates.