Note that the headline mixes messages a bit.  It's 7 times longer than current 
Lithium-Metal cells, not 7 times longer than the Li-ion cells currently in EVs. 
 So it's only 700 cycles, which is still shy of how many cycles Li-ion cells 
already achieve.

Bill

-----Original Message-----
From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of brucedp5 via EV
Sent: Sunday, April 8, 2018 2:24 AM
To: ev@lists.evdl.org
Cc: brucedp5
Subject: [EVDL] EVLN: PNNL’s EV Battery: 7x Longer Lifespan, 2+* Longer Range



https://www.greenoptimistic.com/pnnl-ev-battery-lifespan-range-20180402/
PNNL’s New EV Battery: 7x Longer Lifespan, 2 to 3 Times Longer Range April 2, 
2018  Janina Lazo-Cruz

The transport sector remains a major contributor to greenhouse gas emissions 
and electric vehicles can eliminate this generation of pollutants. Still, there 
are factors that remain challenges to electric mobility.

The miles an electric vehicle can drive before it runs out of charge is almost 
half of the miles a petroleum/diesel-fueled vehicle can drive before it runs 
out of gas. Moreover, the availability of charging stations and the service 
life of batteries are also reasons for car owners to choose conventional 
vehicles.

So, efforts to improve electric mobility experience are seen globally and 
currently, researchers from the Pacific Northwest National Laboratory (PNNL) 
have developed a new formula for battery’s electrolyte solution to enhance its 
performance unprecedentedly in terms of its service life and storage capacity 
or an electric vehicle’s range.

In a separate project, engineers from the University of Colorado, Boulder are 
currently developing a technology for electric vehicles that would allow them 
to recharge wirelessly while running on the road.

Lithium-Metal vs Lithium-Ion Battery

Briefly, a battery is composed of two electrodes (anode and cathode) and an 
electrolyte solution. The solution is a special liquid that contains charges or 
electrolytes, which transports from one electrode to the other.

For lithium-ion batteries, the electrodes are made up of graphite, while 
lithium-metal batteries use lithium metal as their electrodes. Comparing the 
two electrode materials, lithium metal is a much better option as it can store 
two to three times more energy than graphite.

This means that with lithium-metal batteries, electric vehicles can drive two 
to three times farther in a single charge compared with the currently commonly 
used lithium-ion batteries powering our personal electronic devices. As such, 
they are considered as the “holy grail” of energy-storing devices.
New Electrolyte Solution Brings 7 Times Longer Battery Lifespan and 2-3 Times 
Longer EV Range

Acknowledging this fact, PNNL focused on the current challenges and problems of 
lithium-metal batteries. The main problem lies with its electrolyte solution 
that easily corrodes its electrodes, causing shorter battery life or lower 
number of recharging cycles.

Their study published in the journal Advanced Materials found out that 
increasing the concentration of lithium-based salt in the electrolyte solution 
forms a barrier around the electrodes, protecting them from corrosion and 
ultimately, lengthening the battery life.

This technique, however, has two disadvantages: first, the lithium-based salt 
is expensive and second, increasing the salt’s concentration results in 
increasing the viscosity and lowering the conductivity of the electrolyte 
solution.

So, the researchers had to optimize the salt concentration. PNNL senior battery 
researcher Ji Guang “Jason” Zhang said, “We were trying to preserve the 
advantage of the high concentration of salt, but offset the disadvantages. By 
combining a fluorine-based solvent to dilute the high concentration 
electrolyte, our team was able to significantly lower the total lithium salt 
concentration yet keep its benefits.”

By adding the fluorine-based solvent into the electrolyte solution, the 
lithium-based salts become clusters. These salt clusters, in effect, function 
as balls of localized high-concentration lithium salt within the solution that 
can still act as protection to electrodes from corrosion, but its “cluster” 
form avoids its formation of dendrites.

Crystals, such as the lithium-based salt, tend to form dendrites or the 
branch-like structure during crystallization. They are like snowflake formation 
and frost patterns on a glass. Lithium-based salt dendrites are undesirable for 
the battery as they cause short circuits and thus, end the battery’s life.

The performance of this new formulation of electrolyte solution was tested on 
an experimental battery cell as small as a watch battery. While a conventional 
electrolyte solution can maintain its charging capability after just 100 
charge/discharge cycles, the newly developed electrolyte solution can withstand 
up to 700 cycles. That is, the lifespan of a battery is 7 times more than the 
existing batteries.

Wireless Battery Charging

“On a highway, you could have one lane dedicated to charging,” said Khurram 
Afridi, who leads a team of engineers and scientists at CU Boulder on 
developing a technology that enables wireless transferring of electrical energy 
and electric vehicles to charge on the go.

The concept of wireless transfer through electric fields is actually deemed 
impossible because of the very small capacitance created by the large airgap 
between a car and a road.  Nevertheless, for Afridi, “As a scientist, you feel 
challenged by things that people tell you are impossible to do.”

Afridi said, “Everybody said that it’s not possible to transfer that much 
energy through such a small capacitance. But we thought: What if we increase 
the frequency of electric fields?”

Afridi and his team devised pairs of parallel metal plates with each pair 
comprised of a bottom plate and a top plate separated by a 12-centimeter gap. 
The top plates represent the receiving plate attached to a vehicle, while the 
bottom plates are the transmitting plates to be fixed on the road.

The device was shown to transmit kilowatts of power at megahertz-scale 
frequencies. “When we broke the thousand-watt barrier by sending energy across 
the 12-centimeter gap, we were just exhilarated,” said Afridi.

Via EcoWatch [
https://www.ecowatch.com/ev-drive-time-2554094238.html
] ... [© greenoptimistic.com]




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{brucedp.neocities.org}

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