Preparation method of manganous oxide negative electrode material of magnesium ion battery

Abstract

The invention discloses a preparation method of a manganous oxide negative electrode material of a magnesium ion battery. According to the method, the manganous oxide negative electrode material withelectrochemically reversible magnesium-storing performance is prepared through a manganous oxalate pyrolysis method, wherein the reaction equilibrium potential of the material is 0.87V(vs.Mg / Mg<2+>),the granularity of a pyrolysis product under the temperature of 400 DEG C ranges from 30nm to 50nm, the first discharge specific capacity is 39.6mAh / g, the ratio of pseudocapacitance capacity in the specific capacity is large, the redox peak current of the material is slowly lowered along with increase of cycles, and the specific capacity of the material is slowly lowered along with rising of pyrolysis temperature. The method has advantages in terms of granularity control and specific capacity increase of the manganous oxide negative electrode material and is possibly subjected to practical application in the future.

Description

technical field [0001] The invention relates to a negative electrode material of a magnesium ion battery, in particular to a manganese oxide negative electrode material used for a magnesium ion battery. Background technique [0002] Magnesium-ion batteries have high specific energy (magnesium theoretical specific energy reaches 2205Ah / kg, 3832mAh / cm 3 ), stable chemical properties, low price, abundant resources, and environmental friendliness, it is a strong competitor that is expected to replace lithium-ion batteries in the future. However, magnesium-ion battery research is still in its infancy. Among them, based on Mg(BuEtAlCl 2 ) 2 , Grignard reagents, aminomagnesium halide complexes, ionic liquids, polymer gels and other series of electrolytes still have low oxidation potential, poor magnesium deposition-dissolution reversibility, low ionic conductivity, large electrode material interface impedance, Problems such as poor matching with positive electrode materials; po...

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Problems solved by technology

However, magnesium-ion battery research is still in its infancy

Among them, based on Mg(BuEtAlCl 2 ) 2 , Grignard reagents, aminomagnesium halide complexes, ionic liquids, polymer gels and other series of electrolytes still have low oxidation potential, poor magnesium deposition-dissolution reversibility, low ionic conductivity, large electrode material interface impedance, Problems such as poor matching with positive electrode materials; positive electrode materials mainly refer to existing lithium ion battery positive electrode materials, but due to factors such as high charge density of magnesium ions and low oxidation potential of electrolyte, magnesium ions migrate in most positive electrode materials The reversibility of magnesium ion battery is relatively poor, and there are generally problems such as poor structural stability, low reaction potential, and small specific energy; the research on negative electrode materials for magnesium ion batteries is relatively lagging behind, and the reports are limited to Mg, Sn, Sb, Bi metal and its alloys and nano-Li 4 Ti 5 o 12

The surface of Mg and Mg alloy negative electrode materials is easy to form a dense passivation film that is difficult for magnesium ions to pass through, which limits the efficiency of magnesium deposition-dissolution, and may form columnar crystals to cause a short circuit between positive and negative electrodes.

[0003] The theoretical specific capacity of manganese oxide is 755mAh / g, and it has attracted much attention as an anode material for lithium-ion batteries, but its feasibility and electrochemical performance as an anode material for magnesium-ion batteries have not been reported yet.

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