Method for recycling waste lithium vanadium phosphate

Abstract

The invention discloses a method for recycling waste lithium vanadium phosphate. The method comprises the following steps: step one, oxidizing waste lithium vanadium phosphate in a furnace filled withair at 300-600 DEG C for 0.5-3h, and then adding water according to the solid-to-liquid ratio of 1:10-1:3, thus obtaining first slurry; step two, adding calcium salt into the first slurry obtained inthe step one, and then filtering to obtain a solution containing a lithium compound, and filter residues containing vanadium and calcium phosphate; step three, adding water into the filter residues containing vanadium and calcium phosphate according to the solid-to-liquid ratio of 1:7-1:2; and step four, adding sodium carbonate or sodium hydroxide into the second slurry obtained in the step three, enabling the pH value of the solution to be increased to 12.6-14.0, then filtering to obtain sodium orthovanadate solution and calcium phosphate filter residues, and concentrating and crystallizingthe sodium orthovanadate solution to obtain sodium orthovanadate crystals. The recycling method is relatively simple, lithium vanadium phosphate powder in the positive electrode material of a lithiumvanadium phosphate battery can be recycled to obtain the solution containing the lithium compound and the sodium orthovanadate crystals with relatively high purity, and the environment pollution caused by waste lithium vanadium phosphate powder can be prevented.

Description

technical field [0001] The invention relates to the field of recycling waste batteries, in particular to a method for recycling waste lithium vanadium phosphate. Background technique [0002] In the fields of communications and digital products, lithium-ion batteries are being used more and more widely due to their excellent performance, and their output continues to increase. Compared with lithium iron phosphate, lithium vanadium phosphate has become a new hope for power lithium-ion battery cathode materials because of its advantages of high specific capacity, high specific energy, good high-current discharge, especially low-temperature discharge performance. Although lithium vanadium phosphate batteries do not contain mercury, cadmium, lead and other highly toxic heavy metal elements compared with traditional batteries, their positive and negative electrode materials and electrolytes will endanger the environment and human health, and should be recycled. [0003] The Chin...

AI Technical Summary

Problems solved by technology

This patent can finally recover vanadium pentoxide. In order to improve the purity, the production process is very complicated, the parameters to be controlled are relatively strict, and the cost is high. However, the control of production cost in the field of waste recycling is very important, so the above scheme is difficult to implement in practice application

[0004] Sodium orthovanadate is light white transparent needle-like or hexagonal prismatic crystal, easy to weather in the air, white after dehydration, can be used for desulfurization and decarburization of industrial gases, corrosion inhibitor, pharmaceutical industry, photographic industry, and ink manufacturing Many uses such as printing and dyeing and plant inoculation consume a huge amount. If the lithium vanadium phosphate in the positive electrode material of the waste lithium vanadium phosphate battery can be recycled into sodium orthovanadate, it will not only reduce the waste of resources, but also protect the environment. As of the deadline, no reports have been found about sodium orthovanadate recovered from waste lithium vanadium phosphate