Compressed Carbon
2013-2017
Purpose
I came into materials science convinced that the way we design electrodes needed a complete rethink. Batteries were steadily improving, but performance was still constrained by structural trade-offs: higher density meant less surface area and slower ion mobility; more porosity meant weaker density. To me, this signaled that future breakthroughs would not come from chemistry alone but from architectural innovation. At that time, my postdocs were exploring an unconventional route—carbon nano-onions (CNOs), tiny multi-shell fullerenes that could be compacted without collapsing pores. I believed in their idea and committed to helping make it real.
To do so, I set myself the challenge of building a carbon materials lab from scratch in twelve months. My role was part student, part builder, and part facilitator: I learned from the scientific expertise of my team while ensuring they had the infrastructure to succeed. By early 2016, we had transformed a bare room into a functioning laboratory equipped with hot presses, spark plasma sintering rigs, and electron microscopy tools. This environment enabled us to test the bold hypothesis that friction-induced exfoliation of CNOs could yield dense, porous foams capable of delivering both high energy and high power—something long considered contradictory.
Potential
The promise was enormous. Conventional supercapacitors excel at power delivery but typically store just 1–10 Wh kg⁻¹—a fraction of lithium-ion batteries. Our densified CNO foams achieved a volumetric energy density of ~73 Wh L⁻¹ while sustaining 30 kW L⁻¹ of power, a performance band that sits squarely between supercapacitors and batteries. Crucially, despite being ultra-thick, the electrodes delivered 99 % ion accessibility thanks to their interconnected 3D pore networks. This opened the door to new applications: grid-scale storage that charges in seconds, heavy vehicles that recuperate braking energy, or consumer electronics that recharge in the time it takes to make coffee.
To ensure these findings would endure, we formalised them in a patent filing. The document records how spark plasma sintering (SPS) of CNOs could tune density (0.4–1.2 g cc⁻¹), conductivity (20–140 S cm⁻¹), and micropore surface area (200–600 m² cc⁻¹). My colleagues developed the scientific insights; I helped structure the work into a form investors and industry could understand. The IP showed that by balancing micropores (for energy) and mesopores (for power), carbon foams could be tailored for different devices. If scaled, this platform could underpin next-generation storage devices—hybrids that are safe, cost-effective, and environmentally benign.
Process
This project was as much about entrepreneurial grit as science. Setting up the lab meant navigating procurement delays, equipment commissioning, and training staff, all while pushing experiments forward. My postdocs spearheaded the experimental design, but I was hands-on in building the environment: acquiring and calibrating a spark plasma sintering system, coordinating with workshops to fabricate dies, and setting up safety and process control. Together, we created a rapid iteration workflow where ideas could move from powder to test cell in days.
Experimentally, we discovered something counterintuitive. By applying 40–120 MPa and 300–800 °C, we tuned densities between 0.50 and 1.12 g cc⁻¹ and surface areas between 730 and 1280 m² g⁻¹. Transmission electron microscopy tomography confirmed that only ~3 % of pore volume was isolated; the rest formed a continuous network. Most strikingly, densification actually increased micropore surface area by more than 1400 %, showing that sliding nanoparticles exfoliate under pressure. I did not invent this mechanism—that credit belongs to the postdocs—but I was instrumental in ensuring the experiments had the tools, speed, and focus to reveal it.
Precaution
From the start, I stressed the importance of realism alongside ambition. While our materials improved volumetric energy density, they still could not displace lithium-ion on a gravimetric basis. Scaling spark plasma sintering beyond the lab posed challenges: high tooling costs, throughput limitations, and environmental considerations. I often found myself in the role of asking: Does the performance justify the complexity?
The university environment also added constraints. Procurement cycles slowed us down, budgets limited us to a skeleton crew, and we leaned heavily on student researchers. While my postdocs drove the science, I kept the project on track through these obstacles, ensuring we documented both successes and limitations. In hindsight, a dedicated industrial partner might have been the missing piece. Still, by filing the patent and publishing our results, we ensured that the know-how would remain accessible—ready to be revived in the future.
Performance
Despite the challenges, the project delivered tangible milestones. In under a year, we went from an empty basement to a functioning lab, trained a team, and proved that densification can coexist with porosity. The electrodes we produced delivered 73 Wh L⁻¹ energy density and 30 kW L⁻¹ power, approaching lithium-ion performance while retaining supercapacitor-like lifetimes. These results challenged a long-standing assumption in porous materials science.
The most enduring outcome was our patent, which captured both the synthesis and performance parameters. It secured intellectual property while giving us a foundation for further exploration. Personally, this project taught me how to set up a lab from zero, manage a multidisciplinary team, and translate scientific curiosity into IP. My postdocs drove the scientific breakthroughs; I ensured the environment, direction, and persistence that allowed them to succeed. Even though I later moved on, this project remains one of the formative experiences of my career, and the materials themselves remain a promising platform for energy storage—an idea worth revisiting as global demand grows.