A few days ago we learned of CATL’s announcement of the design of a lithium battery of 500Wh/kg, which would revolutionize sectors such as aviation. Now, another Chinese team has confirmed the development of a battery that increases the CATL figures by 42%.
In an article published in the magazine Chinese Physical Lettersresearchers from the Institute of Physics of the Chinese Academy of Sciences in Beijing have confirmed the manufacture of the first prototypes of rechargeable lithium batteries in bag format that have managed to boost their energy and volumetric density to spectacular figures.
These have used an ultra-thick, high-discharge cathode with a surface capacity greater than 10 mAh/cm2, and a lithium-metal anode.
Lithium-metal batteries have been positioned for a few years as an interesting alternative to current lithium batteries. A technology capable of offering benefits such as increased safety, and increased heat tolerance.
For applications such as aviation, safety is one of the keys that in the event of an accident, overload or breakage of the cell, neither an explosion nor a fire will occur. They add that their performance not only does not reduce with heat, but rather improves. Something that will allow, in practice, to eliminate any cooling system from the battery, which will result in more space for the cells and a lower cost.
In the case of the Chinese design, the high charge/discharge voltage of lithium-rich manganese-based oxides allows for greater storage capacity of lithium ions. Scientists identify Li1.2Ni0.13Co0.13Mn0.54O2 as the chemical composition of the cathode.
As the developers explain:The anode electrode employs ultrafine metal lithium incorporated by a spacer coating technique, which addresses the troublesome problem of reversible deposition of ultrafine lithium of large surface capacity.»
The devices have an energy density of 711.3 Wh/kg and a volumetric capacity of 1653.65 Wh/L. Figures that multiply by more than two those of the best current cells on sale, and that place them as the most rechargeable lithium batteries based on a higher density intercalated type cathode.
“With regards to battery manufacturing, our end-battery structure design (including the use of ultra-thin current collectors) was designed to minimize the use of ancillary materials and improve the ratio of active materials throughout the battery. This approach is what allowed such a high energy density”.
The impact of this development, which will have to go from the laboratory to tests to confirm its performance, opens the doors wide to accelerate the electrification not only of road transport, but also in other intensive fields such as aviation and maritime transport. .
The researchers explain that while high-capacity batteries may exist, there is a trade-off between the energy density, cycling performance, power, and safety of lithium cells.
Safety is a primary requirement, but high energy density will also increase risks during battery operation. Something that those responsible for this investigation put on the table who have indicated that: “Energy density should be gradually improved while ensuring safety. Our goal is to improve the safety performance of batteries through solid-state battery technology, making high-density batteries more convenient and stable.”.
The question is when. At the moment, the researchers have not given dates for the arrival of these new batteries, which have their main challenge to overcome in their useful life. A factor that they indicate will need a long time to be resolved. Something that takes us to a medium-term temporary plan that would mean leaving until at least 2027-2028 for the start of its commercial life.
The good news is that, as we can see in the graph published by Cleantechnica, the time between work in the laboratory and its arrival in production is getting shorter over time.
An aspect that indicates that very possibly, by 2030 we will have sufficiently mature battery technology enough to electrify practically all sectors of transport, and have cheap technology to support renewable energy.