Method of recycling waste lithium iron phosphate battery and lithium manganate battery

Abstract

The invention discloses a method of recycling waste lithium iron phosphate battery and lithium manganate battery. The method comprises the following steps of carrying out discharging, disassembling, soaking with an organic solvent, calcining, acid hydrolysis and filtering and the like on the lithium iron phosphate battery and the lithium manganate battery respectively, then mixing filtrates of anode materials of the two kinds of batteries according to a certain ratio, regulating a pH value of a solution to obtain a lithium iron manganese phosphate precursor, adding the lithium iron manganese phosphate precursor in a carbon source, and carrying out high-temperature calcining synthesis reaction to obtain the carbon-cladding lithium iron manganese phosphate anode material. By adopting the method provided by the invention, an anode material of the waste lithium iron phosphate battery and an anode material of the waste lithium manganate are treated by proper chemical means to be used as a manganese source, an iron source, a phosphorus source and a lithium source for synthesizing high-energy density anode material lithium iron manganese phosphate, so that the preparation cost of the lithium iron manganese phosphate is lowered, the recycling efficiency is high, the treatment speed is fast, and a brand new reference mode can be provided for a power battery enterprise to treat waste power batteries.

Description

technical field [0001] The invention relates to the application field of recycling lithium ion batteries, in particular to a method for recycling waste lithium iron phosphate batteries and lithium manganate batteries. Background technique [0002] With the rapid development of new energy vehicles in my country, a large number of lithium-ion power batteries have been applied to new energy vehicles, and the life cycle of lithium-ion power batteries is generally 5-8 years, and some are even shorter. The development also has a history of nearly 10 years, so a large number of waste lithium-ion power batteries are produced over time, and most of them are lithium iron phosphate power batteries and lithium manganese oxide power batteries. Technical problems have not yet been popularized. For such a large number of waste power batteries, the current common practice is to regroup waste power batteries and apply them to the field of energy storage. This method can dispose of a large numb...

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Problems solved by technology

[0002] With the rapid development of new energy vehicles in my country, a large number of lithium-ion power batteries have been applied to new energy vehicles, and the life cycle of lithium-ion power batteries is generally 5-8 years, and some are even shorter. The development also has a history of nearly 10 years, so a large number of waste lithium-ion power batteries are produced over time, and most of them are lithium iron phosphate power batteries and lithium manganese oxide power batteries. Technical problems have not yet been popularized. For such a large number of waste power batteries, the current common practice is to regroup waste power batteries and apply them to the field of energy storage. This method can dispose of a large number of waste lithium-ion power batteries in a short time. However, people also realize that this is only a temporary treatment method, and the performance of lithium-ion batteries will eventually decay to the point where they cannot be reused. Therefore, many battery companies or battery recycling companies are doing waste lithium-ion power battery recycling and regeneration technology.

[0003] In the prior art, it is mentioned that the lithium iron phosphate cathode material is regenerated by a series of means by using the waste lithium iron phosphate battery. However, its electrochemical performance is not as good as that of the first synthesized lithium iron phosphate. It is also reported that phosphoric acid is re-synthesized by acid hydrolysis. Lithium iron phosphate, the performance of lithium iron phosphate synthesized by this method is basically the same as that of lithium iron phosphate synthesized for the first time. However, in the development direction of high energy density of lithium-ion power batteries, lithium iron phosphate batteries are almost close to the bottleneck. The system has become a consensus in the industry. Lithium iron phosphate and lithium iron phosphate have the same crystal structure, but the energy density of lithium iron phosphate is much higher than that of lithium iron phosphate, and the content of each element of lithium iron phosphate is rich and environmentally friendly. It is considered to be the next-generation material system to replace lithium iron phosphate material

However, the current preparation methods of lithium manganese iron phosphate are all synthesized by high-purity chemical reagents, and the cost is relatively high.

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