Magnesium ion battery positive electrode material KVS4/N-TG with K<+> pre-embedded induced multi-electron reaction and application of magnesium ion battery positive electrode material KVS4/N-TG

Abstract

The invention discloses a K<+> pre-embedded magnesium ion battery positive electrode material KVS4 / N-TG capable of inducing multi-electron reaction and application, and belongs to the technical field of battery materials. The method comprises the following steps: preparing ammonium metavanadate into an aqueous solution, then mixing the aqueous solution with an excessive thioacetamide glycol solution, transferring the mixture and a carbon plate which is prepared by adopting a vapor deposition method and on which N-TG grows into a reaction kettle, and carrying out a hydrothermal reaction at 180DEG C for 4h; and drying the product, and pre-embedding K<+> in a K2SO4 solution by using an electrochemical method to obtain the magnesium ion battery positive electrode material KVS4 / N-TG. According to the invention, K<+> is pre-embedded in the intercalation type positive electrode material, so that not only can multi-electron reaction be realized, but also the structural stability of the positive electrode material can be maintained, and the electrochemical performance of the magnesium ion battery is improved. The magnesium ion battery assembled by the composite material has high specific capacity and excellent cycling stability, and has a wide application prospect.

Description

technical field [0001] The invention relates to the technical field of battery materials, in particular to a K + Pre-intercalation-induced multi-electron reaction KVS cathode material for magnesium-ion batteries 4 / N-TG and application. Background technique [0002] Due to the abundant reserves of multivalent elements, batteries based on multivalent metal ions are considered as potential energy storage devices. As a new type of energy storage system, magnesium-ion batteries, due to their high safety, low cost, and high theoretical capacity (3833mAh cm –3 ) have been extensively studied. However, the slow charge migration of divalent magnesium ions will cause problems such as low structural stability, slow kinetics and even low specific capacity. To take advantage of the high charge density of divalent magnesium ions, it is necessary to obtain cathode materials that can achieve both multi-electron transfer and structural stability, which is a major challenge in the develo...

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Problems solved by technology

However, the large volume change caused by the multi-electron reaction makes it difficult for the host material to maintain structural stability, which limits the cycle reversibility and stability of Mg-ion batteries (see literature: Hetero-layered MoS 2 / C composites enabling ultrafast and durable Na storage, Li et al. Energy Storage Mater. 2019, 21, 115-123)

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