It is the preoccupation of not being able to complete a trip, because the battery charge is too low, the next charging station is too far away, or you don't have the time necessary, since with the systems now available it takes several hours.
On average the batteries, if they connect to a household outlet, take about 10 hours to reach full capacity. Stations are also available super recharge like the Tesla Superchargers, which provide ‘fill the tank in about an hour. However, they are only 76 throughout Europe. And the risk is that speed can degrade the battery.
The Office for Energy Efficiency and American Renewable Sources (DOE) believes that recharging is the bottleneck that slows the spread of electric cars. It is no coincidence that last year it funded 12 research projects with $ 19 million to study solutions.
Numerous scientists have set to work trying to design new batteries that are faster and can solve drivers' needs in a short time. But so far this type of performance, which requires you to absorb 400 kilowatts of energy, is a process that risks damaging the battery, shortening the duration.
A first solution was found by a group of researchers from the University of Pennsylvania, which uses a new technology and allows you to reach a 100 percent charge in minutes, or 10 minutes to complete a journey of 3-400 kilometers.
Normally lithium batteries are always charged and discharged at the ambient temperature. However, the researchers found that by heating the lithium anode at a temperature of 60 degrees for a few minutes, and then cooling it, the performance is increased.
In the past it was believed that heat could not be used because secondary effects could have occurred. The materials in fact react with the electrolyte and form a film that consumes lithium, cause resistance and also reduces battery life.
Slow charging is essential to complete the electrochemical reaction without causing damage.
The new method discovered improves the reaction because keeps most of the cold cell during the download process. It is used a sheet of nickel which creates an inner chamber, the only one that is heated.
This structure allows the electrode to warm up in less than 30 secondsand causes the ions to move rapidly towards the negative electrode without causing the formation of the film because they are then rapidly cooled.
Several tests have been done at different temperatures. At 20 degrees, after 60 cycles, performance and duration were reduced. At 60, the number of recharge cycles reached 2,500, or the equivalent of 800,000 kilometers of route.
Almost simultaneously researchers from the Argonne National Laboratory American have discovered another system which allows for faster charging. By exposing the cathode to a concentrated light beam, such as that emitted by a xenon lamp, they managed to halve the time.
Normally the accumulators are put on a dark box. In this case instead they would be put into one transparent box. The factor that allowed this performance was the replacement of lithium with a semiconductor that interacts with light, lithium manganese oxide. By absorbing the photons the manganese passes from a trivalent state to a tetravalent one forcing lithium to emit ions faster.