As a result of scientific and technological innovation over past decades, the number of graphene-based products is growing rapidly throughout the world. Lead-acid is the most widely employed rechargeable system with a 65% share of the market. Although the battery was invented over 150 years, research continues to enhance its performance in terms of rate capability, stability, cycle life and durability [1]. The use of graphene is envisaged to offer further benefits given that it has high intrinsic electrical conductivity and also is extremely lightweight, chemical inert and flexible with a large surface area. The presence of graphene in the electrodes improves the electrical conductivity between the particles of the active mass through preventing thickening and the growth of large lead sulfate particles [2]. 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 subsequently well distributed electrochemical redox reactions throughout the electrode matrix, arrested the formation of too large lead sulfate particles. The addition of graphene 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 novel lead-graphene positive grids in a motive power lead-acid battery designed for e-bike duty. The composite grids have been produced by Chaowei Power Ltd. And to date have been used successfully in over 30 million e-bike batteries. Graphene-lead composites have higher hardness, shorter ageing time and greater corrosion resistance compared with lead-calcium alloys presently employed in lead-acid batteries and thereby show promise for a new-generation of positive grids.

References
[1] Detchko Pavlov, Lead-acid batteries: science and technology (Book), Elsevier 2011.
[2] Mo Shi, Guiping Dai, et al., Synthesis of Graphene and application in lead-acid battery, Chinese LABAT Man, 2015; 52(3): 142-145.