A redesigned metastable phase of vanadium pentoxide (V2O5) shows extraordinary performance as a cathode material for magnesium batteries. The graphic compares the conventional (right) and metastable structures of V2O5.
Credit: Justin Andrews, Texas A&M University
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A team of scientists, led by Texas A&M University, USA, chemist Sarbajit Banerjee, has discovered a metal-oxide magnesium battery cathode material, that could be used to produce batteries that promise higher density of energy storage on top of transformative advances in safety, cost and performance in comparison to their ubiquitous lithium-ion (Li-ion) counterparts.
The team’s solution relies on a redesigned form of an old Li-ion cathode material, vanadium pentoxide, which they proved is capable of reversibly inserting magnesium ions. They reconfigured the atoms to provide a different pathway for the magnesium ions to travel along, which creates a viable cathode material in which they can readily be inserted and extracted during discharging and charging of the battery.
This is achieved by limiting the location of the magnesium ions to relatively uncomfortable atomic positions by design, based on the way the vanadium pentoxide is made – a property known as metastability. This metastability helps prevent the magnesium ions from getting trapped within the material and promotes complete harvesting of their charge-storing capacity with negligible degradation of the material after many charge-recharge cycles.
The development could be a turning point in the field as it highlights the inherent advantages of using more imaginative, metastable materials like this new form of vanadium pentoxide.
A research group, utilizing inexpensive elements, has demonstrated the feasibility of synthesizing electrode materials for lithium-ion batteries (LIBs). If explored further, this method could reduce industrial reliance on rare metals such as cobalt and nickel.
Details of their results were published in ACS Applied Energy Materials on April 11, 2022.
Rare metals are widely used because they form a suitable crystal structure for LIBs’ key component—cathode materials. In these materials, lithium is easily and reversibly extracted/inserted.
Scientists have long sought ways to incorporate other inexpensive elements into the crystal structure. Yet, just like only a certain amount of salt dissolves into water, the solubility of other elements is limited.
