As he smartphone, tablet or laptop that you probably have in your hands, as more and more vehicles and electrical devices of all kinds use lithium-ion batteries, whose most critical point is their limited autonomy and useful life. This relationship of dependence on the plug could end – or at least be mitigated – with Really fast charging systems that recharge batteries in a few moments.
These systems really already exist, and we have seen impressive demonstrations – such as Xiaomi charging a 4,000 mAh mobile in just 17 minutes. What is the problem then? The obstacle to overcome now is to find the key of how to get the batteries to degrade less with this type of charging systems faster and faster.
The industry moves forward, faltering
Manufacturers have been trying for several years save the pitfall of autonomy without finding phones that are unreasonably thicker and heavier, or slow to load. So much so that even when the batteries grow in the terminals more and more, fast charging systems do it at a much faster speed.
An example of this are Oppo chargers. In its 50W SuperVOOC version, it is so good that they started licensing other manufacturers this year, it allowed charge a phone like the Oppo Find X or the RX17 Pro in just over half an hour. And that is enough to change usage habits. Basically, you can load it whenever and wherever you want. Completely.
From hours to minutes when charging
Despite this, for some reason Oppo has been forced to backtrack recently in the implementation of this charging system. Whether for the effects of this on battery health, about what they have not released pledge, or for a purely cost issue In a feature that is not so demanded – in its favor, prices have dropped significantly – its recent Oppo Reno no longer has it.
On the opposite side of the scale is Samsung, which seems to be finally animated with a super fast charging system with his recent Galaxy Note 10. After remaining several generations repeating at 15 W, now they go up to 25 W as standard and up to 45 W in the 'Plus' version we acquire the compatible charger. Huawei also tested in that range already last year with its Huawei Mate 20 Pro.
Meanwhile, Apple still continues to provide 5W chargers standard with its different iPhone models. Of course, it does give the option from the last iPhone to a not so slow charger, much more in the industry average with 18 W chargers that also sold separately. Until then the norm had been to use the standard iPad charger to speed up the process.
Hand in hand, with the next version of the operating system, Apple will introduce a charging system that 'learns' from our uses to try to compensate for the deterioration of the batteries. And it is that lithium-ion batteries degrade more strongly by staying too long at high levels of charge. They will avoid, charging the last percentage only before the usual resumption of use, that spend nights and nights fully charged. This is approximately one third of the total life of the iPhone, keeping the phone at 80% the rest of the time it is plugged in.
The research is clear: fast, a priori, bad loading
Despite the high level of investment, the batteries lithium ion are found relatively stagnant in terms of capacity. It is not, indeed, for lack of desire: the type of batteries that we see in our smartphones they are also similar to those that push electric cars and will increasingly provide backup systems – like Tesla's recent MegaPack – for renewable energy to escape fossils.
Experts recommend using fast charging only when necessary
It is investigated so much that, of the volume of current scientific production, part is directed merely to assimilation tasks. A few months ago the first book was presented written for an AI, and it was nothing more than an attempt to bring together the latest advances – more than 53,000 publications in the last three years, according to Springer– in this type of batteries, crossing hundreds and hundreds of references to different papers published in recent years. The result? A complete disaster of which the first paragraph is not understood, but a gateway to a field – language processing – that is still booming. After all, the algorithm, Beta Writer, it's not called that for nothing.
After almost three decades of commercial development Since Sony introduced the first rechargeable batteries based on lithium ion in 1991, much of the progress is proprietary and a handful of corporations – such as LG, Panasonic or Samsung – keep their progress safe. Batteries are complex systems, and there are several considerations to take into account in their design: their cost, useful life, maximum capacity or resistance to unfortunate events. Little is worth a battery that is extremely good at almost everything, if it fails loudly in a single one of these points.
In any case and regardless of the 'additive' or mixture of compounds used in its manufacture – which favor the different points mentioned above, and of which hundreds have been tested in different proportions – there are certain bases of common consensus in the world of lithium ion batteries that allow to extend its autonomy. Among tips such as reducing exposure to heat or not completely depleting the battery is, without a doubt, that of use your own fast charge only when necessary.
Radiographing the damage
Recently, researchers from Purdue University – which accumulates a good amount of studies and dissemination on the subject – in Indiana, United States, have managed to create a map of the damage accumulated by the batteries themselves internally, both microscopic and macroscopic and in different conditions.
Its starting point is that the battery is not an isolated chemical system in which the charges and discharges are performed in an ideal way. Instead, the system has a also mechanical component linked to the current or voltage with which the battery is charged. And this effect is enhanced by fast charging systems, since there are more abrupt changes in the temperatures and currents of the battery.
Batteries suffer at different scales, and not uniformly
The team, led by Yang Yang, made use of synchrotron radiation in several installations worldwide – in Europe, China and the United States – has managed to create microscopic images of the internal structure of lithium-ion batteries. The study has taken into account the very quantum interaction of the constituents at this very microscopic scale and automatic learning systems have been used to interpret the data.
The images clearly show how this damage to the small particles that form lithium ion batteries It is heterogeneous, both spatially and temporally and at various levels. Loads, temperatures and currents are distributed inconsistently, which forces the acceleration of their deterioration.
The analysis, also performed under fast loading conditions, also determines the breakage patterns of these small particles, but is not reduced to them either. If you look at the images, they are observed accumulations of small breaks in certain regions. Some, much more punished than others – such as in the vicinity of the area that anode and cathode, called separator -, which accelerates the deterioration and instability of the entire battery.
A new angle of improvement, but choose
This confirms the specific effect of fast charging systems on a generic battery, but it is likely that the leading manufacturers who are implementing these systems are doing so without worsening durability. It would be possible simply by improving in a more limited way in other aspects.
More fast load resistance, in the current spotlight
In return, they may be giving up already small gains in energy density or other battery characteristics and turning towards a greater tolerance to fast loading. As Kejie Zhao, one of the researchers authors of the paper"It is difficult for a battery to have a large capacity and be stable at the same time. Increasing its capacity often means sacrificing its stability."
The motivation for the industry behind the production of more and more batteries with this technology would be quite clear: it is of little importance in certain applications if the capacity is marginally superior, but it is a benefit to recover much of it in just a few minutes.