Solution enables a battery with both high efficiency & current density
Dendrites — the microscopic, pin-like fibers that cause rechargeable batteries to short circuit — create fire hazards and can limit the ability of batteries to power our smart phones and store renewable energy for a rainy day.
Now a new electrolyte for lithium batteries that’s described in Nature Communications eliminates dendrites while also enabling batteries to be highly efficient and carry a large amount of electric current. Batteries using other dendrite-limiting solutions haven’t been able to maintain both high efficiencies and current densities.
“Our new electrolyte helps lithium batteries be more than 99 percent efficient and enables them to carry more than ten times more electric current per area than previous technologies,” said physicist Ji-Guang “Jason” Zhang of the Department of Energy’s Pacific Northwest National Laboratory. “This new discovery could kick-start the development of powerful and practical next-generation rechargeable batteries such as lithium-sulfur, lithium-air and lithium-metal batteries.”
Most of the rechargeable batteries used today are lithium-ion batteries, which have two electrodes: one that’s positively charged and contains lithium and another, negative one that’s typically made of graphite. Electricity is generated when electrons flow through a wire that connects the two. To control the electrons, positively charged lithium atoms shuffle from one electrode to the other through another path: the electrolyte solution in which the electrodes sit. But graphite has a low energy storage capacity, limiting the amount of energy a lithium-ion battery can provide smart phones and electric vehicles.
When lithium-based rechargeable batteries were first developed in the 1970s, researchers used lithium for the negative electrode, which is also known as an anode. Lithium was chosen because it has ten times more energy storage capacity than graphite. Problem was, the lithium-carrying electrolyte reacted with the lithium anode. This caused microscopic lithium dendrites to grow and led the early batteries to fail.
Many have tweaked rechargeable batteries over the years in an attempt to resolve the dendrite problem. In the early 1990s, researchers switched to other materials such as graphite for the anode. More recently, scientists have also coated the anode with a protective layer, while others have created electrolyte additives. Some solutions eliminated dendrites, but also resulted in impractical batteries with little power. Other methods only slowed, but didn’t stop, the fiber’s growth.
Concentrated secret sauce
Thinking today’s rechargeable lithium-ion batteries with graphite anodes could be near their peak energy capacity, PNNL is taking another look at the older designs. Zhang and his team sought to develop an electrolyte that worked well in batteries with a high-capacity lithium anode. They noted others had some success with electrolytes with high salt concentrations and decided to use large amounts of the lithium bis(fluorosulfonyl)imide salt they were considering. To make the electrolyte, they added the salt to a solvent called dimethoxyethane.
The researchers built a circular test cell that was slightly smaller than a quarter. The cell used the new electrolyte and a lithium anode. Instead of growing dendrites, the anode developed a thin, relatively smooth layer of lithium nodules that didn’t short-circuit the battery.
After 1,000 repeated charge and discharge cycles, the test cell retained a remarkable 98.4 percent of its initial energy while carrying 4 milliAmps of electrical current per square centimeter of area. They found greater current densities resulted in slightly lower efficiencies. For example, a current density as high as 10 milliAmps per square centimeter, the test cell maintained an efficiency of more than 97 percent. And a test cell carrying just 0.2 milliAmps per square centimeter achieved a whopping 99.1 percent efficiency. Most batteries with lithium anodes operate at a current density of 1 milliAmps per square centimeter or less and fail after less than 300 cycles.
The new electrolyte’s remarkably high efficiency could also open the door for an anode-free battery . . .
The Latest on: Next-generation rechargeable batteries
via Google News
The Latest on: Next-generation rechargeable batteries
- Coldplay's eco-friendly tours will see audience generating electricity as they jump to the musicon October 14, 2021 at 5:44 pm
One one of their most famous tracks, they sing about a world... and it was all yellow. But these days Coldplay and lead singer Chris Martin, 44, (pictured) seem more interested in turning things green ...
- Schneider Electric's Next Generation PowerPacT Circuit Breaker Wins Showstopper Award at NECA Nashville 2021on October 12, 2021 at 10:26 am
Schneider Electric, the global leader in the digital transformation of energy management and automation and the industry's leader in circuit breakers, has won the NECA Showstopper Award following the ...
- SES begins pilot production of solvent-in-salt electrolyte for hybrid Li-metal batterieson October 7, 2021 at 3:01 am
SES Holdings Pte. Ltd. (SES), a developer of high-performance hybrid lithium-metal rechargeable (Li-Metal) batteries for electric vehicles (EVs) and other applications (earlier post), has established ...
- Redmond-based battery maker raises $16M, eyes new R&D facilityon October 6, 2021 at 6:17 pm
The company, which makes rechargeable batteries that can power electric vehicles, consumer electronics and medical devices, says it might add nontechnical jobs to the Seattle area next year.
- SES Begins Electrolyte Pilot Production at Shanghai Facilityon October 6, 2021 at 7:56 am
SES is a next-generation battery technology company ... and initial production of high-performance Li-Metal rechargeable batteries for electric vehicles and other applications.
- AIWA launched Luxury Acoustics Premium Next Generation Hi-Fi Speakerson October 6, 2021 at 7:22 am
All the 6 models are portable, with high power rechargeable batteries and can be used both at home and the outdoors. Feature loaded speakers with unique design and high-end functionality.
- SES Begins Electrolyte Pilot Production at Shanghai Facilityon October 6, 2021 at 7:06 am
SES is a next-generation battery technology company spun-off from ... SES is a global leader in the development and initial production of high-performance Li-Metal rechargeable batteries for electric ...
- SES Begins Electrolyte Pilot Production at Shanghai Facilityon October 6, 2021 at 7:05 am
SES Holdings Pte. Ltd. (SES), a global leader in the development and initial production of high-performance hybrid lithium-metal rechargeable (Li-Metal) batteries for electric vehicles (EVs) and other ...
- BrightVolt Raises $16 Million in Series B Funding Led by New Science Ventures and Caterpillar Venture Capital Inc.on October 6, 2021 at 5:00 am
BrightVolt, Inc., a global leader in the design, development, and manufacturing of safe, high energy and low cost solid-state Lithium-Ion batteries has successfully closed the first tranche of a $16M ...
- Vivarail, Powered by Lithion Battery's Valence Modules, Introduces the First Battery Train in North Americaon October 5, 2021 at 5:41 am
For this exciting rail pilot project, Pop-Up Metro, Vivarail has retrofitted railcars with market leading battery technology, utilizing Lithion Battery's Valence battery modules. The original concept ...
via Bing News