Author: Hálfdán Gunnarsson (University of Iceland) - Lithium batteries are the most dominant type of rechargeable batteries on the market, but their production is both expensive and environmentally detrimental. With increasing demand and rising prices, the search for alternative rechargeable batteries is becoming crucial. A potential solution to this problem is the search for and development of alternative metal-ion batteries, without significantly reducing performance compared to using lithium. Two-dimensional materials have shown great promise as electrode materials for post-lithium metal-ion batteries, especially the MXenes material group. This work investigates the performance of a promising MXene anode material, vanadium carbide (V2C), for use in metal-ion batteries. We use DFT to compare the properties of four promising alternative metal-ions (Na, Mg, Al, Ag) with lithium (Li). Comparison showed that Ag and Al are very interesting candidates to replace Li in metal-ion batteries, where Ag has the same specific capacity as Li, 967 mA h g−1, and a slightly higher OCV of 0.91-1.23 V compared to of 0.75-1.00 V, but Ag has a considerably higher capacity than Li of 2823 mA h g−1 but also a lower OCV of 0.22-0.45 V. Na and Mg also show interesting results, where Na shows similar OCV to Ag and Li of 0.66-1.32 V with a lower OCV of 627 mA h g−1, and Mg shows a similar but slightly higher OCV than Al of 0.39-0.45 V with a lower but significantly high capacity of 1883 mA h g−1. All of the ions show very low diffusive barriers, predicting a high charge/discharge rate.
