Looking for the next leap in rechargeable batteries

February 17, 2017

USC researchers may have just found a solution for one of the biggest stumbling blocks to the next wave of rechargeable batteries -- small enough for cellphones and powerful enough for cars.

In a paper published in the January issue of the Journal of the Electrochemical Society, Sri Narayan and Derek Moy of the USC Loker Hydrocarbon Research Institute outline how they developed an alteration to the lithium-sulfur battery that could make it more than competitive with the industry standard lithium-ion battery.

The lithium-sulfur battery, long thought to be better at energy storage capacity than its more popular lithium-ion counterpart, was hampered by its short cycle life. Currently the lithium-sulfur battery can be recharged 50 to 100 times -- impractical as an alternative energy source compared to 1,000 times for many rechargeable batteries on the market today.

A small piece of material saves so much life

The solution devised by Narayan and lead author and research assistant Moy is something they call the "Mixed Conduction Membrane," or MCM, a small piece of non-porous, fabricated material sandwiched between two layers of porous separators, soaked in electrolytes and placed between the two electrodes.

The membrane works as a barrier in reducing the shuttling of dissolved polysulfides between anode and cathode, a process that increases the kind of cycle strain that has made the use of lithium-sulfur batteries for energy storage a challenge. The MCM still allows for the necessary movement of lithium ions, mimicking the process as it occurs in lithium-ion batteries. This novel membrane solution preserves the high-discharge rate capability and energy density without losing capacity over time.

At various rates of discharge, the researchers found that the lithium-sulfur batteries that made use of MCM led to 100 percent capacity retention and had up to four times longer life compared to batteries without the membrane.

"This advance removes one of the major technical barriers to the commercialization of the lithium-sulfur battery, allowing us to realize better options for energy efficiency," said Narayan, senior author and professor of chemistry at the USC Dornsife College of Letters, Arts and Sciences. "We can now focus our efforts on improving other parts of lithium-sulfur battery discharge and recharge that hurt the overall life cycle of the battery."

Cheap and abundant building blocks

Lithium-sulfur batteries have a host of advantages over lithium-ion batteries: They are made with abundant and cheap sulfur, and are two to three times denser, which makes them both smaller and better at storing charge.

A lithium-sulfur battery would be ideal for saving space in mobile phones and computers, as well as allowing for weight reduction in future electric vehicles, including cars and even planes, further reducing reliance on fossil fuels, researchers said.

The actual MCM layer that Narayan and Moy devised is a thin film of lithiated cobalt oxide, though future alternative materials could produce even better results. According to Narayan and Moy, any substitute material used as an MCM must satisfy some fundamental criteria: The material must be non-porous, it should have mixed conduction properties and it must be electrochemically inert.
-end-
The study was funded by the University of Southern California and the Loker Hydrocarbon Research Institute.

University of Southern California

Related Energy Storage Articles from Brightsurf:

Reviewing multiferroics for future, low-energy data storage
Big data and exponential demands for computations are driving an unsustainable rise in global ICT energy use.

The perfect angle for e-skin energy storage
Researchers at DGIST have found an inexpensive way to fabricate tiny energy storage devices that can effectively power flexible and wearable skin sensors along with other electronic devices, paving the way towards remote medical monitoring & diagnoses and wearable devices.

Upcycling plastic waste toward sustainable energy storage
UC Riverside engineering professors Mihri and Cengiz Ozkan and their students have been working for years on creating improved energy storage materials from sustainable sources, such as glass bottles, beach sand, Silly Putty, and portabella mushrooms.

Chemists advance solar energy storage aimed at global challenges
Multi-university effort develops solar energy storage to enable decentralized electrification systems in remote areas.

Energy-saving servers: Data storage 2.0
A research team of Mainz University has developed a technique that will potentially halve the energy required to write data to servers and make it easier to construct complex server architectures.

Energy storage using oxygen to boost battery performance
Researchers have presented a novel electrode material for advanced energy storage device that is directly charged with oxygen from the air.

New material, modeling methods promise advances in energy storage
The explosion of mobile electronic devices, electric vehicles, drones and other technologies have driven demand for new lightweight materials that can provide the power to operate them.

Finding balance between green energy storage, harvesting
Generating power through wind or solar energy is dependent on the abundance of the right weather conditions, making finding the optimal strategy for storage crucial to the future of sustainable energy usage.

Diamonds shine in energy storage solution
QUT researchers have proposed the design of a new carbon nanostructure made from diamond nanothreads that could one day be used for mechanical energy storage, wearable technologies, and biomedical applications.

Gas storage method could help next-generation clean energy vehicles
A Northwestern University research team has designed and synthesized new materials with ultrahigh porosity and surface area for the storage of hydrogen and methane for fuel cell-powered vehicles.

Read More: Energy Storage News and Energy Storage Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.