Breakthrough in Ultracapacitor Technology: Microsecond Charging Now Possible

A groundbreaking ultracapacitor design, also known as an electric double-layer capacitor (EDLC), was unveiled in the journal Science in 2010, potentially revolutionizing the landscape of portable electronics and energy storage systems. What’s new since then?

Since the groundbreaking ultracapacitor design, also known as an electric double-layer capacitor (EDLC), was unveiled in the journal Science in 2010, there have been several significant developments in ultracapacitor technology:

Ultracapacitors: Bridging the Gap Between Capacitors and Batteries

Ultracapacitors have long been recognized for their ability to charge and discharge within seconds, making them invaluable in applications such as regenerative braking systems. However, the latest innovation pushes the boundaries even further, addressing scenarios where even a few seconds of charging time is considered too long.

Nanoscale Innovation: Graphene Fins for Ultra-Fast Charging

Researchers in the United States have developed an ultracapacitor utilizing nanometer-scale fins of graphene. This novel design has resulted in a device capable of charging and discharging in less than 200 microseconds, a significant leap forward in energy storage technology[1].

The Science Behind Ultracapacitors

Ultracapacitors store charge in electric fields between conducting surfaces. The larger the surface area of these conducting surfaces, the more charge the device can hold. This principle allows ultracapacitors to bridge the gap between traditional capacitors and batteries, providing more energy than the former and faster delivery than the latter[1].

Breakthrough Electrode Design

A team led by Dr. John Miller, president of JME (an electrochemical capacitor company based in Shaker Heights, Ohio), has significantly enhanced the ultracapacitor’s speed by redesigning its electrodes. The new electrode, developed by Dr. Ron Outlaw from the College of William and Mary in Williamsburg, Virginia, features sheets of graphene standing vertically on a graphite base[1].

Key Features of the New Electrode:

• Graphene sheets are one atom thick
• Grown using plasma-assisted chemical vapor deposition
• Graphite base is 10 nanometers thick
• Design resembles “rows of 600-nanometer tall potato chips standing on edge”

Implications for Future Technology

This advancement in ultracapacitor technology opens up new possibilities for various applications:

• Smaller and lighter portable electronic devices
• More efficient energy harvesting systems
• Improved power management in electric vehicles
• Enhanced performance in renewable energy storage

Why Can’t I Instantly Charge My Phone with an Ultracapacitor?

While ultracapacitors have made significant advancements since the 2010 announcement, there are several reasons why we can’t instantly charge phones with them yet:

Key Challenges

1. Energy density: Despite improvements, ultracapacitors still have lower energy density compared to lithium-ion batteries. This means they can’t store as much energy in the same volume, which is crucial for mobile devices.
2. Voltage characteristics: Ultracapacitors have a linear discharge curve, meaning their voltage drops as they discharge. This is challenging for electronics that require a stable voltage supply.
3. Size and integration: Current ultracapacitor technology would require devices that are too large to fit comfortably in a smartphone form factor.
4. Cost: While costs have decreased, ultracapacitors are still generally more expensive than batteries for the amount of energy they can store.
5. Charging infrastructure: Instant charging would require not just device-side changes, but also significant upgrades to charging infrastructure to handle the extremely high power delivery needed.

Progress Being Made

However, progress is being made:

1. Hybrid systems: Some researchers are working on hybrid systems that combine ultracapacitors with batteries to get the best of both worlds.
2. Material advancements: New materials like graphene and carbon nanotubes are improving energy density and performance.
3. Structural supercapacitors: Recent innovations include structural supercapacitors that could potentially be integrated into device casings.
4. Micro-supercapacitors: Ultramicro-supercapacitors have been developed, which are orders of magnitude smaller than previous designs.

The Future

While we’re not at the point of instant phone charging yet, these advancements suggest that ultracapacitors may play a larger role in mobile device energy storage in the future, potentially enabling much faster charging times, if not quite instantaneous.

While this breakthrough is significant, further research is needed to scale up the technology for commercial applications. However, the potential for microsecond charging in ultracapacitors represents a major step forward in energy storage solutions, promising to reshape various industries in the coming years.

As we continue to push the boundaries of what’s possible in energy storage, innovations like this graphene-based ultracapacitor bring us closer to a future of ultra-fast charging devices and more efficient energy utilization across multiple sectors.