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Pressurized carbonization is known to improve carbon content and create textural changes in resultant carbon compared to conventional (atmospheric) carbonization. However, further studies investigating the impact of these carbonization methods on the graphitic quality of the carbon precursors have not been explored exten- sively. This study investigates the influence of carbonization methods on the graphitization behavior of soft and hard carbons using a three-model system: phenolic resole (hard carbon), polyvinyl chloride (PVC) (soft carbon), and a 50:50 blend of resole and PVC. Carbonization was conducted under autogenic pressure (AGP) and at- mospheric pressure (APP) at 500◦C for 5 h, followed by high-temperature treatment at varying temperatures. Various techniques, including X-ray diffraction and Raman spectroscopy showed hard carbon precursors exhibited improved properties under AGP carbonization such as larger crystallite size, sharp crystalline peaks, lower ID/IG ratio, and narrow G-full width half-maximum, an indication of improved crystallinity by lowering amorphous phase at high temperature. For soft carbon precursors, the method of carbonization did not impact the graphitization level. The most significant finding was the enhanced crystalline nature observed in hard carbon under AGP conditions, without the need for any catalyst. It shows the influence of pressure on improving the crystallinity of hard carbon precursors.
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This content will become publicly available on May 9, 2026
TEMPLATING INDUCED GRAPHITIZATION BY GRAPHENE OXIDE DERIVED ADDITIVES: PHENOLIC RESINS, BIOMATERIALS AND ENERGY STORAGE APPLICATIONS
Interest in graphitizing hard carbons has peeked in recent years due to the applications of graphitic carbon in energy storage applications and the need to transition to greener energy and transportation. Hard carbons have initially been graphitized with the use of metal catalysts but a downside to this method is the occurrence of metal impurities in the resultant graphitic carbon which then makes it detrimental to applications. Moreover, the process of purification could also be costly. This dissertation aims to present a novel technique—templating using 2-dimensional (2D) nanomaterials—to graphitize model hard carbons. The scope of this dissertation answers the following: ❖ Does carbonization pressure affect the graphitization of soft and hard carbons? ❖ Are the characteristics/properties of 2D nanomaterials effective in templating and aiding graphitization of model hard carbons? ❖ What mechanisms are operative during templating graphitization and what are their contributions? ❖ How do the properties of the modified hard carbons influence their performance in energy storage applications? To address the aforementioned questions, in-depth studies, and novel processes were employed. The first part of this thesis explores the role of carbonization pressure in the graphitization of model soft and hard carbons. The model soft and hard carbons were subjected to carbonization under autogenic and atmospheric pressure conditions and their graphitic evolution at different high temperatures treatments was characterized. Next, the thesis explores the effect of 2D nanomaterials in the form of graphene oxide and its derivatives in inducing the graphitization of phenolic resin, novolac. Two mechanisms were identified (physical and chemical templating) as operative in aiding the graphitization of the novolac matrix. The thesis further explores the templating technique on the graphitization of a biomaterial, lignin, where methods were employed to improve the interactions between the lignin matrix and the graphene oxide additives. The results from the above-described work in the phenolic resin and biomaterial prompted the need for an in-depth understanding of the templating mechanisms and their contributing factor to graphitization. In this regard, the thesis then scrutinizes the predominant force and operative mechanism driving graphitization— physical templating versus chemical templating. Finally, the thesis assesses the influence of the properties of modified hard carbons in energy storage applications and provides strategies for performance improvement. Collectively, the important contribution of this thesis is centered on the development of 2D nanomaterial templating in inducing graphitization of hard carbons (which requires no purification process for the resultant graphitic carbon), understanding the templating mechanisms interplay in modifying and tailoring crystalline properties in hard carbons and lastly, highlighting the electrochemical performance of the modified hard carbons in energy storage applications.
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- Award ID(s):
- 2306042
- PAR ID:
- 10610412
- Publisher / Repository:
- Penn State University
- Date Published:
- Subject(s) / Keyword(s):
- Reduced graphene oxide (RGO) Graphene oxide (GO) Novolac Oxygen content Templating, graphitization
- Format(s):
- Medium: X
- Institution:
- Penn State University
- Sponsoring Org:
- National Science Foundation
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