Will lithium batteries be replaced by magnesium batteries? Will the "post-lithium battery" era come?

Nowadays, lithium batteries have become an indispensable device in daily life and have been applied in many fields, such as mobile phones, electric vehicles , satellites, spacecraft, underwater robots, etc. The reason why lithium-ion batteries are widely used is that they have high voltage, low self-discharge, long cycle life and good safety performance.

But its disadvantage is that it is expensive, and as humans move towards renewable energy, a technology that can store more electricity is needed. At the same time, lithium, nickel, and cobalt, the key materials for lithium-ion batteries , are only found in a few places, and not all of them can be used for battery production. Therefore, countries have accelerated the layout of the "post- lithium battery " era.

Recently, a joint team E-Magic, composed of Cambridge University in the UK, well-known engineering universities in Denmark and Israel, and research institutions in Germany and Spain, has set its sights on magnesium. Magnesium ions can carry two positive charges, while lithium ions can only carry one, so in theory, the energy density of magnesium batteries can be greater than that of lithium batteries.

In addition, the production areas of lithium battery raw materials - lithium, nickel and cobalt - are extremely unevenly distributed. Nearly 80% of lithium resources are concentrated in four lakes in the Americas and six mines in Australia; 78% of nickel resources are concentrated in Indonesia, Australia, Brazil, Russia, Cuba and the Philippines; and about 51% of the world's proven cobalt resources are distributed in the Democratic Republic of the Congo.

In contrast, the reserves of sodium, magnesium and zinc are much higher. For example, the reserves of lithium in the earth's crust are 0.0065%, and the global reserves are only 86 million tons, while the reserves of sodium in the earth's crust are 2.74%, and the sodium salt reserves in the Qaidam Basin of China alone reach 321.6 billion tons.

On the other hand, magnesium batteries still have many technical and material obstacles to overcome. Due to the small size, high charge density and strong polarization of magnesium ions, it is difficult to insert them into most matrices and form embedded compounds. Therefore, the positive electrode materials available are limited.

In addition, magnesium reacts with water. The reported electrolyte systems include Grignard reagent solution, MgrhICL-AICL/THFMg (Snphb) 2 and other organic electrolytes, but these organic electrolytes may release gas during the charge and discharge process, which poses certain safety risks. Combined with these reasons, it may take some time to completely replace lithium batteries.

Previously, CATL developed the first generation of sodium-ion batteries . The battery has an energy density of 160Wh/kg and can reach 80% of its capacity after charging for 15 minutes at room temperature. The development of zinc batteries and aluminum batteries has also made different progress. However, in general, their maturity is still far from large-scale commercial application, and they are even still in the laboratory stage.

Therefore, whether and when the "post-lithium battery" era will arrive remains to be seen.