Battery Improvements

[EdEarl]

Two promising battery improvements, 200,000 charges and 5x energy density would make electric cars lighter, probably less expensive to purchase, and certainly less expensive over a lifetime.

 

 

200,000 charges April 20, 2016

 

Scientists have long sought to use nanowires in batteries. Thousands of times thinner than a human hair, they're highly conductive and feature a large surface area for the storage and transfer of electrons. However, these filaments are extremely fragile and don't hold up well to repeated discharging and recharging, or cycling. In a typical lithium-ion battery, they expand and grow brittle, which leads to cracking.

 

UCI researchers have solved this problem by coating a gold nanowire in a manganese dioxide shell and encasing the assembly in an electrolyte made of a Plexiglas-like gel. The combination is reliable and resistant to failure.

 

The study leader, UCI doctoral candidate Mya Le Thai, cycled the testing electrode up to 200,000 times over three months without detecting any loss of capacity or power and without fracturing any nanowires. The findings were published today in the American Chemical Society's Energy Letters.

We recently replace our Prius battery after eight years operation. Current batteries are limited 7000 charges; although, fewer charges is more common. Two hundred thousand (or more) charges is more than 25 times battery life, 8*25=200 years. That's ten human generations instead of 2/5 of a generation.

 

If this technology scales up for mass production, large battery size, and low cost, it will be important.

 

 

5x Density October 29, 2015

 

Scientists have developed a working laboratory demonstrator of a lithium-oxygen battery which has very high energy density, is more than 90% efficient, and, to date, can be recharged more than 2000 times, showing how several of the problems holding back the development of these devices could be solved.

 

Lithium-oxygen, or lithium-air, batteries have been touted as the 'ultimate' battery due to their theoretical energy density, which is ten times that of a lithium-ion battery. Such a high energy density would be comparable to that of gasoline - and would enable an electric car with a battery that is a fifth the cost and a fifth the weight of those currently on the market to drive from London to Edinburgh on a single charge.

If the prediction of 1/5 cost and weight can be achieved in mass production for large batteries, it will be a game changer, even at 2000 charges.

 

If these two technologies can be married, a 200,000 charge lithium air battery could make tailpipes obsolete. Even if these two technologies cannot be married, this research hints that battery research will improve both number of charges and power density, and sets goals for researchers. Even 20,000 charges and doubling energy density would be big.

[Ken Fabian]

The former sounds highly applicable to and desirable for renewable energy systems. The latter sounds useful for electrification of transport; approaching the energy density of hydrocarbons would mean viable electric aircraft. 2000 cycles is still insufficient working life but it's heartening to know that the well of innovation in energy storage is deep and not running dry.

[EdEarl]

Jet aircraft seem unlikely to be displaced by electric propeller aircraft, because cruising speed an altitude would be limited to about P51 Mustang performance. Propeller aircraft amount to less than half of the planes sold in the general aviation market of $25B in 2014. Jets are more expensive than propeller aircraft; thus, sales of general aviation jets contributes most of that $25B. Jets dominate the much larger commercial market.

 

It is possible that AI pilots and electric airplanes could be inexpensive enough to spawn a short-haul taxi service; for example DC to Philly, London to Bristol, Amsterdam to Brussels, etc. This market would need a VTOL aircraft along the lines of the Osprey. It could land at a heliport, yet fly fast as a winged aircraft.

 

Seems to me the price of a small electric aircraft would be greater than most people could afford, even though they would probably be less expensive than a comparable piston engine aircraft.

Edited April 22, 2016 by EdEarl

[Enthalpy]

You can perfectly run a fan from an electric motor. A fan fits an electric motor even better than a propeller, since it permits a higher peripheral speed. Remember: in an airliner motor, the gas turbine serves just to rotate the fan, which is a propeller design optimized for higher air speed. Batteries or fuel cells are the true limit. Fuel cells improve, so a commmuter plane would fly properly right now, a M0.7 long-hauler soon.

http://www.scienceforums.net/topic/73798-quick-electric-machines/#entry738806 (cell mass /2 since that message)

 

As for battery progress: do NOT believe press papers nor science paper. It's charlatanism. To get half-way credible information, go to the science paper and read what has been achieved. It's usually 60dB below what the authors promise as a far result of their research, and press papers report only the promises.

[Sensei]

I have other idea: cover roads with material producing electricity from the Sun. There is large area: same as highways area, which is absorbing 16% from 1050 W/m² at max 170 W/m², currently available technology. The better solar panels technology the better percentage of energy absorbed.

Currently people thought about using car surface to gather all energy needed for car. Small area, small energy absorbed.

But highway has extremely large area overall, it can gather energy from dozen meters, hundred meters, km around car,

and pass to cars/devices above it, levitating or traveling above it..

That requires complete rethinking "fuel" idea, "energy" idea, and "car"/"vehicle" idea.

Instead of getting energy from fuel, use road to gather energy for cars/vehicles to run, literally forever, as long as Sun exists.

 

Car could have permanent magnets in its body.

While road making electromagnets using energy from the Sun.

Causing body of object levitating above it.

Then there is needed very little energy to cause movement.

 

The whole idea about batter for car will be meaningless..

Edited June 16, 2016 by Sensei

[Phi for All]

Seems to me the price of a small electric aircraft would be greater than most people could afford, even though they would probably be less expensive than a comparable piston engine aircraft.

 

I've always wondered if the ultralight plane industry would benefit from electric engines.