The energy capacity of the batteries can be increased by almost 1.5 times
Russian chemists have found a way to increase the energy capacity of alkaline batteries and accumulators almost one and a half times by studying the properties of concentrated lithium salts. This is stated in an article published in the journal Electrochimica Acta.
Today, scientists are actively looking for replacements for lithium-ion power supplies, which are used in various digital gadgets, autonomous medical devices, industrial instruments and space probes. The capacity of lithium-ion batteries is relatively low, which is why their use in electric vehicles and other devices that require “industrial” energy reserves is limited.
The simplest way to solve this problem, as noted by Oleg Drozhzhin, a chemist at Moscow State University, is to increase the operating voltage of the battery: the higher it is, the more energy it can store. However, this is not easy, since each type of electrolyte that fills accumulators and batteries is “sharpened” to work with specific voltages, and lowering or increasing it can drastically reduce the efficiency or life of the power supply.
An additional problem, as noted by Russian scientists, is that an increase in the concentration of lithium salts in an electrolyte can make it unstable – this also interferes with an increase in the capacity and durability of lithium-ion batteries. The existing solutions to this problem, alternative types of lithium salts, as noted by Drozhzhin, have a high cost, which is why they are rarely used in practice.
Russian chemists decided to find a compromise between high voltage stability, high efficiency and electrolyte cost. To do this, they used a well-known, stable and fairly cheap lithium salt, its combination with fluorine and boron, and studied the high-voltage stability of solutions based on it at high concentrations of the substance.
Experiments have shown that a solution of lithium tetrafluoroborate (LiBF4) can store energy at high voltages, while an increase in its concentration does not lead to the destruction of the battery electrodes, explosions and other side effects. Moreover, these batteries behaved more stable than their “regular” cousins, and lost less capacity when recharged – it did not drop with increasing salt concentration.
Drozhzhin and his colleagues hope that their idea will find application in industry in the near future and will be used to create new types of alkaline batteries, the key component of which is not lithium, but sodium or potassium. Such batteries will not be more capacious than their lithium counterparts, but they will cost less, which will allow them to be used as “electricity banks” for large industrial facilities.
The work of Russian scientists from Moscow State University and Skoltech was supported by a grant from the Russian Science Foundation (RSF) as part of the Presidential Program of Research Projects. Source: ria.ru