Phosphor-doped nano silicon lithium ion battery negative material and preparation method thereof

Abstract

The invention relates to a phosphor-doped nano silicon lithium ion battery negative material and a preparation method thereof. The method comprises that a simple silicon nano-material is added into anethanol solution in the liquid-solid ratio of 3-6L/Kg, and stirred to obtain a nano silicon ethanol slurry; a phosphor source is added into the nano silicon ethanol slurry in the Si:P mol ratio of 1:0.0094-0.0360, stirred, and dried to obtain a first mixed material; the first mixed material is thermally insulated at the temperature of 750-1050 DEG C in the protective atmosphere for 4-10h, and cooled to obtain a second mixed material; and the second mixed material is added to a 5wt% of hydrofluoric acid solution in the liquid-solid ratio of 40-60L/Kg, immersed, washed, and dried to obtain thephosphor-doped nano silicon lithium ion battery negative material. Technology is simple, operation is convenient, and the prepared phosphor-doped nano silicon lithium ion battery negative material isstable in structure and high in electrochemical circulation performance.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery negative electrode materials. In particular, it relates to a phosphorus-doped nano-silicon lithium-ion battery negative electrode material and a preparation method thereof. Background technique [0002] Under the circumstances of energy crisis and increasingly serious environmental pollution problems, one of the important means to pursue sustainable development is to develop renewable and low-pollution new energy sources. Among them, the energy source of vehicles is gradually tilted from fossil fuels to new energy storage batteries. Lithium-ion batteries have the advantages of high operating voltage, high specific energy, wide operating temperature range, stable discharge, small size, and light weight. They are considered to be high-capacity , The ideal choice for high-power power batteries has become a hot spot in the industry. The traditional lithium-ion battery anode material is c...

AI Technical Summary

Problems solved by technology

[0004] At present, amorphous carbon is usually used for carbon coating, such as the patented technology of "a preparation method of silicon-carbon anode material for lithium-ion batteries" (CN107634208A). The amorphous carbon layer used in it has limited improvement in the conductivity of composite materials, and the carbon layer The inhomogeneity of the lithium-ion battery can easily cause pore blockage; chemical vapor deposition (CVD) is mostly used for thin film formation, such as the patented technology of "a lithium-ion battery negative electrode material and its preparation method" (CN103280581A), whose preparation process is complicated and not suitable for industrial production; The alloying of silicon is mostly compounded with active metals, such as the patented technology of "Preparation method of aluminum-silicon alloy and aluminum-silicon alloy" (CN108504885A). Although the silicon-active metal material has a high specific capacity, it will also be pulverized due to the active metal itself. Phenomenon, thus poor cycle performance

Images