Sustainable highly conductive electrode materials from ultrathin carbon nanofiber aerogels derived from nanofibrillated

May 24, 2018, Wiley
Sustainable highly conductive electrode materials from ultrathin carbon nanofiber aerogels derived from nanofibrillated
Credit: Angewandte Chemie International Edition

Carbon aerogels are ultralight, conductive materials, which are extensively investigated for applications in supercapacitor electrodes in electrical cars and cell phones. Chinese scientists have now found a way to make these electrodes sustainably. The aerogels can be obtained directly from cellulose nanofibrils, the abundant cell-wall material in wood, finds the study reported in the journal Angewandte Chemie.

Supercapacitors are capacitors that can take up and release a very large amount of energy in a very short time. Key requirements for electrodes are a large surface area and conductivity, combined with a simple production method. Another growing issue in supercapacitor production—mainly for smartphone and electric car technologies—is sustainability. However, sustainable and economical production of as supercapacitor materials is possible, propose Shu-Hong Yu and colleagues from the University of Science and Technology of China, Hefei, China.

Carbon aerogels are ultralight conductive materials with a very . They can be prepared by two production routes: the first and cheapest starts from mostly phenolic components and produces aerogels with improvable conductivity, while the second route is based on graphene- and carbon-nanotube precursors. The latter method delivers high-performance aerogels but is expensive and non-environmentally friendly. In their search for different precursors, Yu and colleagues have found an abundant, far less expensive, and sustainable source: wood pulp.

Well, not really wood pulp, but its major ingredient, nanocellulose. Plant cell walls are stabilized by fibrous nanocellulose, and this extractable material has very recently stimulated substantial research and technological development. It forms a highly porous, but very stable transparent network, and, with the help of a recent technique—oxidation with a radical scavenger called TEMPO—it forms a microporous hydrogel of highly oriented cellulose nanofibrils with a uniform width and length. As organic aerogels are produced from hydrogels by drying and pyrolysis, the authors attempted pyrolysis of supercritically or freeze-dried nanofibrillated cellulose hydrogel.

As it turns out, the method was not as straightforward as expected because ice crystal formation and insufficient dehydration hampered carbonization, according to the authors. Here, a trick helped. The scientists pyrolyzed the dried gel in the presence of the organic acid catalyst para-toluenesulfonic acid. The catalyst lowered the decomposition temperature and yielded a "mechanically stable and porous three-dimensional nanofibrous network" featuring a "large specific surface area and ," the authors reported.

The authors also demonstrated that their wood-derived carbon worked well as a binder-free electrode for supercapacitor applications. The material displayed electrochemical properties comparable to commercial electrodes. The method is an interesting and innovative way in which to fabricate sustainable suitable for use in high-performance electronic devices.

Explore further: Airy but thirsty: Ultralight, flexible, fire-resistant carbon nanotube aerogels from bacterial cellulose

More information: Si-Cheng Li et al. Wood-Derived Ultrathin Carbon Nanofiber Aerogels, Angewandte Chemie International Edition (2018). DOI: 10.1002/anie.201802753

Related Stories

Energy storage of the future

October 20, 2014

Personal electronics such as cell phones and laptops could get a boost from some of the lightest materials in the world.

Rubbery carbon aerogels greatly expand applications

March 19, 2018

Researchers have designed carbon aerogels that can be reversibly stretched to more than three times their original length, displaying elasticity similar to that of a rubber band. By adding reversible stretchability to aerogels' ...

Recommended for you

Interfacing with the brain

June 15, 2018

The nervous system is loaded with encoded information: thoughts, emotions, motor control. This system in our bodies is an enigma, and the more we can do to understand it, the more we can do to improve human life. Brain-machine ...

Electronic skin stretched to new limits

June 15, 2018

An electrically conductive hydrogel that takes stretchability, self-healing and strain sensitivity to new limits has been developed at KAUST. "Our material outperforms all previously reported hydrogels and introduces new ...

Researchers can count on improved proteomics method

June 15, 2018

Every cell in the body contains thousands of different protein molecules and they can change this composition whenever they are induced to perform a particular task or convert into a different cell type. Understanding how ...

Modern alchemists are making chemistry greener

June 14, 2018

Ancient alchemists tried to turn lead and other common metals into gold and platinum. Modern chemists in Paul Chirik's lab at Princeton are transforming reactions that have depended on environmentally unfriendly precious ...

This is what a stretchy circuit looks like

June 14, 2018

Researchers in China have made a new hybrid conductive material—part elastic polymer, part liquid metal—that can be bent and stretched at will. Circuits made with this material can take most two-dimensional shapes and ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.