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Graphene nano-sheets such as graphene oxide, chemically converted graphene and pristine graphene [1-8] improve the capacity utilization of the positive active material of the lead acid battery. At 0.2C, graphene oxide in positive active material produces the best capacity (41% increase over the control), and improves the high-rate performance due to the higher reactivity at the graphene/active material interface. The in-situ changes in the graphene structure and oxygen states [1-2] support these, as well as higher adsorptive surface area, better graphene/lead dioxide interfacial reaction, and finer & highly utilized lead dioxide phases. The multi-scale physio-chemical mechanisms improving capacity and cycle life is thus: Electrolyte/ionic permeation improvements results from increase in pre-formation porosity, and higher interfacial reactivity at gel zone which enhances active material reversibility. Our ion transfer model reveals the optimized redox reaction in the electro-active zone of graphene-enhanced active materials. This work shows the best enhancement in the capacity of lead-acid battery positive electrode till date.

This is an exceptional process on low cost, low defect and high-quality graphene which is produced by sonication in PPC and microwaving for just 5sec. Low energy arc-discharging process expands electrolytic graphite rods into hierarchical-like 3D- graphene retaining the basal plane carbon crystalline order and chemical purity. Sonication in Polypropylene Carbonate causes non-covalent PPC-π bonding at graphene basal plane, aligning the graphene sheets in directions that allows efficient transmission of cavitation pressures and exfoliation; while microwave treatment for 5s separates any layered graphene, utilizing thermally induced lattice vibrations without changes on surface properties. Produced graphene (XRD 2θ = 26 ⁰C) has low defect (0.05 < ID/IG < 0.2), retainment of chemical purity (0~2.5% O2 content), with optimized effective graphene sizes (ranging from 350nm to 35 um), for diverse applications, dispersibility in diverse solvent, conformability to flat semi-transparent surfaces; storable in concentrated slurry (>50 mg mL−1)., † Dr Dada is Director of Engineering, NanoScale and Advanced Manufacturing Lab, Signature EcoSystem Ltd. *Oluwaseun John Dada received his PhD in Mechanical Engineering Nanotechnology Concentration at Hong Kong University of Science and Technology, Hong Kong.

Low cost, low defect and high-quality graphene have been produced in three simple exfoliation steps as a fully tested commercial concept. Low energy thermal arc-discharging expands the electrolytic graphite rod electrodes into hierarchical-like 3D graphene retaining the graphite structural order on a basal plane and chemical purity. Multi-size ball milling causes movement of the graphene materials in multi-shear directions, with optimized speed of the balls and lesser time. Micro-waving further separates the graphene sheets by “thermal expansion and release” mechanism utilizing thermally induced lattice vibrations. This also causes higher lattice order on basal plane improving directional and surface properties. The produced graphene (XRD 2theta = 26 degrees) has low defect (I(D)/I(G) between 0.05 and 0.2), retains chemical purity (between 0.56 and 2.4% change in oxygen content), and with comparatively optimized effective nano-sizes (ranging from 300nm to 35um). These properties make the graphene suitable for diverse applications, dispersibility in various solvents, conformability to flat semitransparent surfaces, and storable in concentrated slurries (>50 mg mL−1) or powder. Keywords: Low Defect; 2D Planar; Arc Discharge Graphene; PPC Sonication; 5 Sec Microwaving; Exfoliation; Electronics. References O.J. Dada, " In-Situ Electrochemical Functionalization of Reduced Graphene Oxide: Positive Lead Acid Case. " ECS Trans., vol. 66, no. 14, pp. 19–30, Aug. 2015. O.J. Dada, “ In-Situ Electrochemical Functionalization of Reduced Graphene Oxide: Positive Lead Acid Case.,” ECS Abstract., MA2015-01 (870), April 2015. O.J. Dada and D. Villaroman, " Superior Electronic and Dielectric Properties of Corrugated ElectrochemicallyReduced Graphene over Graphene Oxide Papers " Journal of the Electrochemical Society, vol 166 no.2, pp D1-D16, 2019. O.J. Dada, " Functional Cathodic and Anodic Transition of Graphene Oxide Paper in Lead Acid Battery System and Its Electrochemistry ". Materials Today: Proceedings”, vol. 3, no. 8, 2688-2697, 2016. O.J. Dada, " Interconnected Graphene Networks as Novel NanoComposite for Optimizing Lead Acid Cathode ". IEEE NANO 2015- Int. Conf. Nanotechnology, Rome, 2015. O.J. Dada, " Higher Capacity Utilization and Rate Performance of Lead Acid Battery Electrodes Using Graphene Additives ”. Journal of Energy Storage, vol. 23, pp579-589, Jun. 2019. O.J. Dada, " Effect of the Size and Conductivity of Tailored Graphene Electro-Catalysts, Lead Acid Battery Cathode as a Case ". IEEE NANO 2015- Int. Conf. Nanotechnology, Rome, Italy, 2015. O.J. Dada, " Wrinkled Graphene Oxide Synthesis by Electrolytic Arc Discharge of Graphite Rods and Slightly Modified Hummer’s Process ". Available at SSRN 3368351, 2019. O.J. Dada, " Highly Ordered Commercial Graphene Manufactured from 3 Simple Steps ". Available at SSRN 3335369, 2019. O.J. Dada, " Low Defect Planar Graphene Exfoliation by Sonication in Polypropylene Carbonate and 5 sec Microwaving ". Available at SSRN 3386581, 2019. O.J. Dada, " Utilization of Hard Carbon as a Substitute for Graphite As Efficient Lithium Battery Anode Material ". Available at SSRN 3368403, 2019. O.J. Dada, “ High Performance Lithium Battery Anodes from Non-Water based Graphene ”. Available at SSRN 3368433, 2019. O.J. Dada, “ Free Standing Porous Graphene and Reduced Graphene Papers Manufactured from Sedimentation of Arc Discharge of Graphite Rods ”. Available at SSRN 3481786, 2019. O.J. Dada, " Corrigendum to “Higher capacity utilization and rate performance of lead acid battery electrodes using graphene additives” . Journal of Energy Storage, vol. 23, pp579–589, Jun. 2019.

Free Standing Porous Graphene and Reduced Graphene Papers manufactured from Sedimentation of Arc Discharge of Graphite Rods. At SignEcoTech, novel and newer nano-carbons such as hard carbons, homogenized graphene, low defect highly crystalline graphene’s, and wrinkled graphene [1-14]. Here, Graphene Oxide papers have been synthesized previously by flow-directed assembly, where the pressure of air within the assembly supports graphene oxide sheets in their nano-crystalline colloidal solution being filtered on nano-porous filter paper. However in this research, we haven’t used any filter paper, or directed flow assembly, but sedimentation of the colloidal solution in ethyl alcohol in a dish. Then, the wrinkled the hierarchical GO sheets fall under gravity by sedimentation. Wrinkling in GO was enhanced by low defects, multi-layer clusters, and variegated + edge interaction amongst graphene clusters, as such the sedimented graphene papers were porous, intertwined and free standing. The composition of GO was confirmed by XPS, while the low defect level clearly marked by higher planar order and low ID/IG band. The wrinkled, multilayer clusters and carbonic surface properties of the graphene oxide sheets enhanced fast sedimentation, evaporation of the alcohol and formation of porous GO structure. The porous reduced\GO morphology is captured by optical microscope. Keywords: Wrinkled GO Papers, Reduced Graphene, Arc Discharge, Modified Hummers Method

Graphene additives have been rightly used in enhancing the capacity and cyclic performance of lead acid battery. However, the fundamental mechanisms of the enhancements in terms of electrochemical characteristics is still unclear. This study focuses on the mechanistic understanding of graphene enhancements within the interphase of the lead acid battery positive electrode in terms of charge transfer resistance and double layer capacitance on adding three graphene additives of pristine graphene, reduced graphene and graphene oxide. Reaction kinetics is greatly enhanced by reduced charge transfer resistance and high electroactive surface area (Rct) which ensures fast desorption of ions at the agglomerate interphase. Significant reduction in Rct of reduced graphene optimized samples was resulted from its larger size due to agglomeration. Electrochemical double layer capacitance or surface charge capabilities enhances discharge performance. Optimized samples had lower charge transfer resistances and were marked by increased peak current values indicating increased faradaic and non-faradaic pseudo-capacitive processes. GO, CCG and GX within the electrode interphase has the capability to store charges in the presence of H+/OH- ions. The double layer capacitances of the graphene electrodes were higher at maximum charge partly due to agglomeration in the CCG, and similarly with GX which has a higher conductivity.

The transition in the composition, electrical and fracture properties of graphene oxide paper (GO) in at the anode (aGO) and cathode (cGO) of lead /sulphuric acid boundary have been studied. Higher thermal stability and lower weight loss of aGO (34wt% at 800 °C) with XRD peak at 2ϴ = 10.5° showed the reduction of the ordinary GO paper (95wt% at 800 °C). The fractographs from the SEM showed that the cGO failed by ductile rupture of a higher degree than the ordinary GO paper, while that of the aGO was brittle cleavage. UV-Vis, Fourier Transform Infrared and X-ray Photoelectron Spectroscopies showed the changes in functional groups, via the interaction of graphene oxide functional groups with protons, adsorbed oxygen containing ions. Graphene/lead oxide based composite was achieved by covalent interactions. Non-covalent complexation of metal ions with slight reduction gave rise to stronger graphene oxide paper at the cathode. The electrical conductivity of aGO are 1.61 x 106 S/m and those of the cGO are 4.27 X 105 S/m. This foremost work is useful for further study of graphene oxide electrochemical reduction and metallic oxide functionalization for electrode materials in advanced lead-carbon batteries.

Interconnected graphene/PbO composites appearing sand-wish was developed for lead acid battery cathode. Facile processing technique which is solution based, enabled the interaction between graphene oxide nano-sheets and PbO submicron particles under mechanical stirring producing sand-wish-like structures containing graphene nano-sheets. The affinity and interaction between graphene oxide and PbO in solution were marked by changes in graphene surface chemistry. Electrodes appeared porous and interconnected, and recording approx. 15% increase in discharge performance.

The effect of reduced graphene electro-catalysts and their the agglomerate sizes, the case in lead acid battery positive active material was done. Reduced graphene size distributions were achieved via shear induced fragmentation of graphene oxide paper followed by hydrazine reduction. Increased size of agglomerates were beneficial when conductive reduced graphene was used as an electro-catalyst, and up to 14% improvements in discharge performance were recorded.

Wrinkled Graphene Oxide has been produced from both glow electrolytic thermal arc discharging of graphite rods combined with hummer’s process. Wrinkling in GO was enhanced by low defects, multilayer clusters, and variegated-edge interaction amongst graphene clusters. The composition of GO was confirmed by XPS, while the low defect level clearly marked by higher planar order and low ID/IG band. The GO morphology is captured by optical microscope and TEM. While arc discharge maintains the graphitic quality of the GO, the slightly modified hummer’s process did not introduce as much defects as the GO used in previous works. The wrinkled GO dispersion is optimal for quenching for DNA biosensors, and it is also applicable for similar high volume and high storage modulus epoxy composites, and other diverse materials and energy applications. REFERENCES -O. J. Dada, " In-Situ Electrochemical Functionalization of Reduced Graphene Oxide: Positive Lead Acid Case. " ECS Trans., vol. 66, no. 14, pp. 19–30, Aug. 2015 -O. J. Dada, “ In-Situ Electrochemical Functionalization of Reduced Graphene Oxide: Positive Lead Acid Case.,” ECS Abstract., MA2015-01 (870), April 2015. -O. J. Dada and D. Villaroman, " Superior Electronic and Dielectric Properties of Corrugated ElectrochemicallyReduced Graphene over Graphene Oxide Papers " Journal of the Electrochemical Society, vol 166 no.2, pp D1-D16, 2019. -O. J. Dada, " Functional Cathodic and Anodic Transition of Graphene Oxide Paper in Lead Acid Battery System and Its Electrochemistry ". Materials Today: Proceedings”, vol. 3, no. 8, 2688-2697, 2016. -O. J. Dada, " Interconnected Graphene Networks as Novel NanoComposite for Optimizing Lead Acid Cathode ". IEEE NANO 2015- Int. Conf. Nanotechnology, Rome, 2015. -O. J. Dada, " Higher Capacity Utilization and Rate Performance of Lead Acid Battery Electrodes Using Graphene Additives ”. Journal of Energy Storage, vol. 23, pp579-589, Jun. 2019. -O. J. Dada, " Effect of the Size and Conductivity of Tailored Graphene Electro-Catalysts, Lead Acid Battery Cathode as a Case ". IEEE NANO 2015- Int. Conf. Nanotechnology, Rome, Italy, 2015. -O. J. Dada, " Wrinkled Graphene Oxide Synthesis by Electrolytic Arc Discharge of Graphite Rods and Slightly Modified Hummer’s Process ". Available at SSRN 3368351, 2019. -O. J. Dada, " Highly Ordered Commercial Graphene Manufactured from 3 Simple Steps ". Available at SSRN 3335369, 2019. -O. J. Dada, " Low Defect Planar Graphene Exfoliation by Sonication in Polypropylene Carbonate and 5 sec Microwaving ". Available at SSRN 3386581, 2019. -O. J. Dada, " Utilization of Hard Carbon as a Substitute for Graphite As Efficient Lithium Battery Anode Material ". Available at SSRN 3368403, 2019. -O. J. Dada, “ High Performance Lithium Battery Anodes from Non-Water based Graphene ”. Available at SSRN 3368433, 2019. -O. J. Dada, “ Free Standing Porous Graphene and Reduced Graphene Papers Manufactured from Sedimentation of Arc Discharge of Graphite Rods ”. Available at SSRN 3481786, 2019. -O. J. Dada, " Corrigendum to “Higher capacity utilization and rate performance of lead acid battery electrodes using graphene additives” . Journal of Energy Storage, vol. 23, pp579–589, Jun. 2019.

High performance lithium battery anode plates were made from processed arc discharge graphene. Arc discharge graphene has been produced from glow electrolytic thermal arc discharging of graphite rods [1-3], different from graphene or reduced graphene prepared through other means [4-11], because it maintains high crystallinity and planar characteristics of graphite marked by low ID/IG and XRD peak (2θ = 26 ⁰C). Arc discharge Graphene was sonicated in NMP for hours until fully exfoliated and able to film coat without impediments on the rougher side of the electrode copper film. Sonicated Graphene was dried in the vacuum oven. Anode plates were prepared by homogenizing the sonicated graphene in PVDF saturated NMP (0.53% NMP; 4% superP carbon black; and 2.25wt% PVDF) for 1 hr. The anode slurry was coated on the copper plates using automatic doctor blade film coater at a speed of 100mm/min. Anode plates were dried at 80 ⁰C for and cured for 120 ⁰C for 2 hrs in vacuum oven. Coin cells of NMC//HGR were made and tested in CT2001A. The capacity of the anode cycled at 1C was ~1083mAhg-1. This very high capacity of the graphene anode represents 188.3% increase over nominal graphite anodes, and one of the highest reported in published literature.