Process for producing battery-grade iron phosphate by high-iron method

Abstract

The invention discloses a process for producing battery-grade iron phosphate by a high-iron method, which is simple in process and low in cost. The process comprises the following steps: (1) reacting high-purity iron with nitric acid to prepare iron nitrate for later use; (2) adding quantitative ferric nitrate and phosphoric acid in proportion, and dissolving and mixing completely; (3) heating the chemical mixed solution prepared in the step (2) to 70-83 DEG C, and then adding a certain proportion of iron phosphate inducer; and (4) stirring under the temperature condition of 70-83 DEG C, directly reacting for 12-16 hours, obtaining a solid-liquid mixture when the solution is clarified and white precipitates are generated, carrying out solid-liquid separation on the solid-liquid mixture, and drying the separated solid iron phosphate, meanwhile, volatilizing and decomposing nitric acid contained in the solid ferric phosphate in a high-temperature environment, wherein the nitric acid solution can be circularly used for preparing a ferric nitrate raw material required by the process; and (5) dehydrating the solid at 400-500 DEG C to obtain anhydrous iron phosphate.

Description

Technical field: [0001] The invention relates to a process for producing battery-grade iron phosphate by a high-speed iron method. Background technique: [0002] For lithium-ion batteries, its wide application mainly depends on the battery's capacity, charge and discharge performance, price and safety. The further improvement of the performance of lithium-ion batteries depends to a large extent on the improvement of the performance of cathode materials, and the reduction of the manufacturing cost of lithium-ion batteries also depends on the reduction of the cost of cathode materials to a large extent. Therefore, the development of positive electrode materials with excellent performance, price and safety has become the focus of lithium-ion battery research. As an important member of lithium-ion batteries, lithium iron phosphate batteries have unparalleled advantages and are known as the safest batteries in the field of power batteries. The cathode material of lithium iron p...

AI Technical Summary

Problems solved by technology

The obtained iron phosphate product needs to consume a large amount of water for washing to remove the acid radicals in the iron phosphate, and the consumption of clean water and subsequent sewage treatment also lead to higher production costs

In addition, the production process needs to adjust the PH value, resulting in stricter process conditions. As a result of the above, the cost of iron phosphate obtained by the above-mentioned traditional iron phosphate production process is relatively high, and the environmental pollution is relatively large.

[0005] The other is the process described in the patent No. 2014100621789, titled "A Battery-Grade Iron Phosphate and Its Preparation Method". Although the cost of this method is lower than that of the previous method, its reaction process will Produce ammonium nitrate solution, which is an explosive substance, which leads to potential safety hazards in the production process. In order to improve production safety, manufacturers need to be equipped with safety facilities in case of emergency, and this process method also requires ammonia water for PH value adjustment, the process conditions are also more complicated

Leading to still higher cost of iron phosphate products