As the vital part of lithium ion batteries, conductive additives play important roles on the electrochemical performance of lithium ion batteries. They construct a conductive percolation network to increase and keep the electronic conductivity of electrode, enabling it charge and discharge faster. In addition, conductive additives absorb and retain electrolyte, allowing an intimate contact between the lithium ions and active materials. Carbon nanomaterials are carbon black, Super P, acetylene black, carbon nanofibers, and carbon naotubes, which all have superior properties such as low weight, high chemical inertia and high specific surface area. They are the ideal conductive additives for lithium ion batteries. This review will discuss some registered patents and relevant papers about the carbon nanomaterials that are used as conductive additives in cathode or anode to improve the electrochemical performance of lithium ion batteries.

Porous carbon nanotubes (PCNTs) were synthesized and incorporation of MnO nanoparticles inside PCNTs (MnO–PCNTs) was successfully achieved by simple pyrolysis of conjugated microporous polymer (CMP) nanotubes and manganese acetate adsorbed CMP nanotubes, respectively. PCNTs exhibit good performance as anode materials for lithium ion batteries. The performance of PCNTs can be further enhanced by incorporation of MnO nanoparticles. MnO–PCNTs show excellent cycling stability (572.6 mA h g⁻¹ after 300 cycles at 1C) and large rate performance (160.8 mA h g⁻¹ at 30C), which are much higher than carbon nanotubes (CNTs) supported MnO composites (MnO–CNTs). This may be due to the unique structure of MnO–PCNTs, where MnO nanoparticles are located inside the tubes, preferably resolving the pulverization issue of MnO during repeated charge–discharge cycles.

Fayalite (α-Fe ₂ SiO ₄ ) with an orthorhombic crystalline structure delivers an initial discharge/charge capacity of 849.0 mA h g ⁻¹ /514.5 mA h g ⁻¹ and a second discharge/charge capacity of 504.9 mA h g ⁻¹ /489.5 mA h g ⁻¹ at a current rate of 0.1 C.