CN-116130647-B - Manganese iron hydrogen phosphate material and preparation method and application thereof

Abstract

The invention discloses a manganese iron hydrogen phosphate material, and a preparation method and application thereof. Relates to the technical field of battery materials. The chemical formula of the ferric manganese hydrogen phosphate material is Fe x Mn (1‑x) HPO 4 , wherein x is 0.1-0.7. According to the manganese hydrogen phosphate iron material, manganese is added into the manganese hydrogen phosphate iron material, so that when the manganese hydrogen phosphate iron material is used for a lithium battery, the platform voltage is as high as 4.1v, and compared with a lithium iron phosphate battery, the cycle life can be greatly prolonged in a gradient manner.

Inventors

• LIU LIWEI
• LIU SEN
• LIU ZHICHENG
• DING JIANHUA
• XIONG XIANGLIANG
• LI FANGPING
• LI FANGMING
• YIN YUQI

Assignees

• 贵州雅友新材料有限公司

Dates

Publication Date

20260512

Application Date

20221118

Claims (10)

1. 1. The ferromanganese hydrogen phosphate material is characterized by comprising the following chemical formula: Fe x Mn (1-x) HPO 4 ; Wherein x is 0.1-0.7; the preparation method of the ferromanganese hydrogen phosphate material comprises the following steps: Mixing ferrous salt solution, divalent manganese salt solution and phosphate solution with the same concentration, and reacting to obtain ferric manganese hydrogen phosphate; in the mixing process, the feeding volume ratio of the ferrous salt solution to the divalent manganese salt solution is 2-3:7-8 in the first 1/3 time, the feeding volume ratio of the ferrous salt solution to the divalent manganese salt solution is 5-6:5-6 in the middle 1/3 time, and the feeding volume ratio of the ferrous salt solution to the divalent manganese salt solution is 7-8:2-3 in the later 1/3 time.
2. 2. A method for preparing the iron-manganese hydrogen phosphate material according to claim 1, which is characterized in that: The method comprises the following steps: Mixing ferrous salt solution, divalent manganese salt solution and phosphate solution with the same concentration, and reacting to obtain ferric manganese hydrogen phosphate; in the mixing process, the feeding volume ratio of the ferrous salt solution to the divalent manganese salt solution is 2-3:7-8 in the first 1/3 time, the feeding volume ratio of the ferrous salt solution to the divalent manganese salt solution is 5-6:5-6 in the middle 1/3 time, and the feeding volume ratio of the ferrous salt solution to the divalent manganese salt solution is 7-8:2-3 in the later 1/3 time.
3. 3. The method of claim 2, wherein the ferrous salt comprises at least one of ferrous sulfate, ferrous nitrate, and ferrous chloride.
4. 4. The method of claim 2, wherein the divalent manganese salt comprises at least one of divalent manganese sulfate, manganese nitrate, and manganese chloride.
5. 5. The method of claim 2, wherein the phosphate comprises at least one of disodium hydrogen phosphate and sodium dihydrogen phosphate.
6. 6. The method according to claim 2, wherein the concentration of each of the ferrous salt solution, the divalent manganese salt solution and the phosphate solution is 0.4 to 1.0mol/L.
7. 7. A process according to claim 2, wherein inert gas is introduced to exclude air when mixing the ferrous salt solution, the divalent manganese salt solution and the phosphate solution.
8. 8. The method according to claim 2, wherein the ratio of the amount of the phosphate solution to the sum of the amounts of the ferrous salt solution and the manganous salt solution is 1:1.2 to 1.4.
9. 9. The method according to claim 2, wherein the temperature is 35-60 ℃ and the temperature of the reaction is 80-90 ℃ during mixing of the ferrous salt solution, the divalent manganese salt solution and the phosphate solution with the same concentration.
10. 10. The use of a ferromanganese hydrogen phosphate material according to claim 1 in batteries in electric vehicles.

Description

Manganese iron hydrogen phosphate material and preparation method and application thereof Technical Field The invention relates to the technical field related to battery materials, in particular to a manganese iron hydrogen phosphate material, a preparation method and application thereof. Background At present, the automobile power lithium battery in the market mainly comprises a ternary lithium battery and a lithium iron phosphate battery, wherein the ternary lithium battery has the characteristics of high voltage (3.7V) of a single platform and high theoretical gram capacity (278 mAh/g). However, the voltage of the single lithium iron phosphate battery is 3.2V, the theoretical gram capacity is 170mAh/g, so that the energy density of the lithium iron phosphate battery is obviously lower than that of a ternary lithium battery, the volume energy density and the low-temperature performance of the lithium iron phosphate battery are also poorer than those of the ternary lithium battery, but the ternary lithium battery needs to use nickel cobalt manganese materials, particularly the nickel cobalt materials have higher price, and a large number of inlets are also needed. The self structural characteristics of the nickel cobalt material lead to relatively poor safety, easy thermal runaway and far shorter cycle life than that of the lithium iron phosphate material. In contrast, the lithium iron phosphate battery has higher safety and better cycle performance, the low-temperature performance can be improved through vehicle-mounted auxiliary heating, and the low-temperature performance can be not considered in most southern areas, so that the energy density of the lithium iron phosphate battery is greatly improved. Based on this, it is highly desirable to provide a novel material for increasing the energy density of lithium iron phosphate batteries. Disclosure of Invention The first technical problem to be solved by the invention is as follows: a ferromanganese hydrogen phosphate material is provided. The second technical problem to be solved by the invention is as follows: a preparation method of the ferromanganese hydrogen phosphate material is provided. The third technical problem to be solved by the invention is: The application of the ferric manganese hydrogen phosphate material. In order to solve the first technical problem, the invention adopts the following technical scheme: A ferromanganese hydrogen phosphate material, the ferromanganese hydrogen phosphate material having the chemical formula: FexMn(1-x)HPO4; wherein x is 0.1-0.7. According to the embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects: According to the manganese hydrogen phosphate ferromanganese material, manganese is added into the ferromanganese hydrogen phosphate material, so that when the manganese hydrogen phosphate ferromanganese material is used for a lithium battery, the platform voltage is as high as 4.1V, and compared with a lithium iron phosphate battery, the cycle life can be greatly prolonged in a gradient manner. In order to solve the second technical problem, the invention adopts the following technical scheme: a method of preparing the iron manganese hydrogen phosphate material, comprising the steps of: Mixing ferrous salt solution, divalent manganese salt solution and phosphate solution with the same concentration, and reacting to obtain ferric manganese hydrogen phosphate; in the mixing process, the feeding volume ratio of the ferrous salt solution to the divalent manganese salt solution is 2-3:7-8 in the first 1/3 time, the feeding volume ratio of the ferrous salt solution to the divalent manganese salt solution is 5-6:5-6 in the middle 1/3 time, and the feeding volume ratio of the ferrous salt solution to the divalent manganese salt solution is 7-8:2-3 in the later 1/3 time. According to the embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects: 1. According to the invention, the iron-manganese ratio of the inner core and the outer shell of the material is changed by controlling the feeding speeds of the divalent manganese salt and the ferrous salt, so that manganese is enriched in the inner core of the crystal, the dissolution of manganese in the charge-discharge process is avoided, iron is enriched in the outer layer of the material, and the conductivity and the cycle life of the material are improved. 2. The excess ratio of phosphate to metal salt is stabilized by controlling the flow rate of phosphate during the reaction process. According to one embodiment of the invention, the total feed flow of the ferrous salt solution and the divalent manganese salt solution is constant during the reaction, the ferrous salt feed rate is high in the initial stage of the reaction, the divalent manganese salt feed rate is low as the reaction proceeds, the ferrous salt feed