As a result of scientific and technological innovation over past decades, the number of products based on carbon nanotubes (CNTs) is growing rapidly throughout the world. Lead–acid is the most widely employed rechargeable battery system with a 65% share of the global battery market. Although the battery was invented over 150 years ago, research continues to enhance its performance in terms of rate capability, stability, cycle-life, and durability. The use of CNTs is envisaged to offer further benefits given that the material has high intrinsic electrical conductivity and is extremely lightweight, chemical inert and flexible with a large surface-area. The presence of CNTs in the electrodes improves the electrical conductivity between the particles of the active mass through preventing the thickening and growth of large lead sulfate particles. This feature is attributed to the formation of a stable and conductive matrix that enables homogeneous delivery and distribution of current to all parts of the active material. By enabling a uniform current distribution and, consequently, well-distributed electrochemical redox reactions throughout the electrode matrix, the formation of excessively large particles of lead sulfate is arrested. The addition of CNTs is also considered to increase both the mechanical stability and electrical integrity of the electrodes and to induce uniform changes in the active mass during charge–discharge cycling. This presentation discusses the commercial application of CNTs in a motive-power lead-acid battery that is designed for e-bike duty.
North Carolina Central University
Dr Guiping Dai conducts research at the North Carolina Central University. His team focuses on the development of next-generation motive-power battery technology. He has worked extensively in the preparation of graphene, carbon nanotubes and other novel nanocarbons via chemical vapour deposition, plasma torches, arc-discharge and chemical solutions, and in their consequent applications in batteries, supercapacitors and electrochemical energy storage.