Power Generation and Distribution Blog

Blemishes are a thing of beauty in graphene paper. Graphene is the world's thinnest material. Researchers at Rensselaer Polytechnic Institute (RPI), have made the grapheme into paper and then zapped it with a laser or camera flash to blemish it with countless cracks, pores, and other imperfections. This turns the graphene into an anode material that can be charged or discharged 10 times faster than conventional graphite anodes used in today's lithium (Li)-ion batteries.

^{Li-ion battery. Image Credit: HowStuffWorks}

We all know rechargeable Li-ion batteries. They are the industry standard for mobile phones, laptop and tablet computers, electric cars, and a range of other devices. The batteries have a high energy density and are able to store large amounts of energy. But due to their low power density, they take about an hour to charge and are unable to quickly accept or discharge energy.

The Need

Electric cars run on Li-ion batteries, but they cannot be totally dependent on them yet for high-power functions such as accelerations and braking. The RPI team sought to solve this problem by creating a new battery that can hold large amounts of energy, but also quickly accept and release this energy. The over-arching goal is to create a battery that will alleviate the need for the complex pairing of Li-ion batteries and super-capacitors in electric cars. This means a simpler, better-performing automotive engine based solely on high energy, high-powered Li-ion batteries. The new batteries could shorten the time it takes to charge portable electronic devices.

^{Difference between electric and gas powered cars. Image Credit: hybridcars.com/electric-car}

"Li-ion battery technology is magnificent, but truly hampered by its limited power density and its inability to quickly accept or discharge large amounts of energy. By using our defect-engineered graphene paper in the battery architecture, I think we can help overcome this limitation," said Koratkar, the John A. Clark and Edward T. Crossan Professor of Engineering at Rensselaer. "We believe this discovery is ripe for commercialization, and can make a significant impact on the development of new batteries and electrical systems for electric automobiles and portable electronics applications."

^{Graphene. Image Credit: Wikipedia}

The Process

The study, published in ACS Nano, discusses the use of graphite in today's Li-ion batteries. Graphene is a derivative from graphite, made of an atom-thick sheet of carbon atoms arranged like a Nanoscale chicken-wire fence. The graphite was slow to charge because lithium ions could only physically enter or exit the battery's graphite anode from the edges, and slowly work their way across the length of the individual layers of graphene. The solution the RPI team developed was to create a sheet of graphene oxide papers, about the thickness of printer paper. The sheet was exposed to either a laser or a flash from a digital camera, which gave off enough heat to cause "mini-explosions" within the paper. The explosions happen as the oxygen is expelled from the paper, leaving the graphene covered with blemishes. The process also causes the paper to expand five-fold in thickness, creating large voids between the individual graphene sheets.

^{Graphene paper blemishes. Image Credit: Rensselaer Polytechnic Institute}

The lithium ions can now use the pores and cracks as shortcuts to move quickly into or out of the graphene. This greatly increased the battery's overall power density. The experimental anode material could charge 10 times faster than conventional anodes in Li-ion batteries, without incurring a loss in energy density. The robust graphene paper was able to perform successfully after more than 1,000 charges/discharge cycles. The process of making the graphene paper anodes for Li-ion batteries can easily be scaled up and the paper can be made in many shapes and sizes. The photo-thermal exposure by laser or camera flashes is an easy and inexpensive process to replicate.

The next step for the research team is to pair the graphene anode material with a high-power cathode material to construct a full battery that can be used in applications such as communication devices, electronics, and electric cars.

Resources

Batteries Made From World's Thinnest Material Could Power Tomorrow's Electric Cars

In the wake of the Solyndra controversy, there's been plenty of criticism leveled at how money was lent to the company. Even so, another company, SolarReserve, has taken out an even bigger loan. SolarReserve's CEO swears that his company won't make Solyndra's mistakes. Do you still believe in assistance to start-up companies like these? Or was Solyndra a warning that it shouldn't be tried again?

The preceding article is a "sneak peek" from Power Generation & Distribution, a newsletter from GlobalSpec. To stay up-to-date and informed on industry trends, products, and technologies, subscribe to Power Generation & Distribution today.

Demand for power just keeps going up, and experts are divided on the best way to handle that. While some are calling for a switch to clean and renewable energy, others say nuclear power is the way to go — and still others say that natural gas supplies are plentiful and cheap. Where do you come down on this issue? If demand is going to keep going up, what's the smartest — and cheapest — way to address that demand?

The preceding article is a "sneak peek" from Power Generation & Distribution, a newsletter from GlobalSpec. To stay up-to-date and informed on industry trends, products, and technologies, subscribe to Power Generation & Distribution today.

The University of Texas (Austin) recently released an energy poll with a dismal conclusion: less than 14% think America is headed in the correct direction in terms of energy, and many respondents think the country should do more with renewable energy. Do you agree with the poll's conclusion? Or do you think that America is on the right track, and that renewable energy is over-hyped?

The preceding article is a "sneak peek" from Power Generation & Distribution, a newsletter from GlobalSpec. To stay up-to-date and informed on industry trends, products, and technologies, subscribe to Power Generation & Distribution today.

With the Solyndra controversy, green energy jobs have come under fire, but is this criticism fair? Huffington Post opinion columnist Keith Brooks says no. As project manager for Blue Green Canada, Brooks says labor unions believe green energy and manufacturing will lead to more jobs, better pay, safer work conditions, and cleaner workplaces.

The preceding article is a "sneak peek" from Power Generation & Distribution, a newsletter from GlobalSpec. To stay up-to-date and informed on industry trends, products, and technologies, subscribe to Power Generation & Distribution today.

The Solyndra failure and subsequent scandal stirred up plenty of headlines. But did it do damage to the solar power industry? Or did it actually help? Some say that Solyndra failed precisely because solar panels have become more affordable, meaning Solyndra's product was overpriced by comparison. Did all the attention and discussion make people more aware of what's happening with clean energy, or do you think Solyndra's mistakes hurt the industry as a whole?

The preceding article is a "sneak peek" from Power Generation & Distribution, a newsletter from GlobalSpec. To stay up-to-date and informed on industry trends, products, and technologies, subscribe to Power Generation & Distribution today.