# US 12,113,215 B2 · Preparation method for Prussian blue sodium-ion battery positive electrode material

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- Number: US 12,113,215 B2
- Document ID: US12113215B2
- Status: Granted
- Kind: B2
- Application number: 18/555,558
- Filed: 2022-07-29
- Published: 2024-03-14
- Granted: 2024-10-08
- Earliest claimed: 2021-10-26
- Assignees: Guangdong Brunp Recycling Technology Co., Ltd.; Hunan Brunp Recycling Technology Co., Ltd.; Hunan Brunp Ev Recycling Co., Ltd.
- Applicants: Guangdong Brunp Recycling Technology Co., Ltd.; Hunan Brunp Recycling Technology Co., Ltd.; Hunan Brunp Ev Recycling Co., Ltd.
- Inventors: Haijun Yu; Yinghao Xie; Aixia Li; Xuemei Zhang; Changdong Li
- Web page: https://patentgrep.com/patent/US12113215B2

## CPC

- H01M 4/58: of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- C01C 3/12: Simple or complex iron cyanides
- H01M 10/054: Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
- C01P 2004/03: obtained by SEM
- C01P 2006/40: Electric properties
- H01M 2004/028: {Positive electrodes}
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C01C: AMMONIA; CYANOGEN; COMPOUNDS THEREOF ({metal hydrides, monoborane, diborane or addition complexes thereof C01B6/00}; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; azides C01B21/08; {compounds other than ammonia or cyanogen, containing nitrogen, non-metals and optionally metals C01B21/082}; metal imides or amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; compounds containing silicon C01B33/00; compounds containing boron C01B35/00)
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Disclosed is a preparation method for a Prussian blue sodium-ion battery positive electrode material, comprising: adding a first nonionic surfactant and an antioxidant into a sodium ferrocyanide solution to obtain a first solution; adding a second nonionic surfactant into a transition metal salt solution to obtain a second solution; in a protective atmosphere, adding the second solution into the first solution for a precipitation reaction; aging after the reaction has finished; collecting a precipitate, washing same, and carrying out vacuum drying on the washed precipitate; then soaking same in an alcohol solution containing sodium alkoxide; and then filtering same and steam drying to obtain a Prussian blue sodium ion battery positive electrode material. The method may relieve vacuum drying pressure and shorten drying time.

## Claims

### Claim 1

A preparation method of a positive electrode material for Prussian blue analogue sodium ion battery, comprising steps of:
adding a first nonionic surfactant and an antioxidant to a sodium ferrocyanide solution to obtain a first solution;
adding a second nonionic surfactant to a transition metal salt solution to obtain a second solution;
under a protective gas atmosphere, adding the second solution to the first solution for precipitation reaction, aging after the reaction is finished, collecting a precipitate, and washing; and
vacuum drying the washed precipitate, then soaking in an alcohol solution containing sodium alkoxide, filtering, and evaporating to dryness to obtain a positive electrode material for Prussian blue analogue sodium ion battery;
wherein the first nonionic surfactant and the second nonionic surfactant are independently one or both of polyethylene glycol and polyoxyethylene alkyl amide alcohol; the first nonionic surfactant is the same as the second nonionic surfactant; molecular weights of the first nonionic surfactant and the second nonionic surfactant are both ≥1500 g/mol; a concentration of the first nonionic surfactant in the first solution and a concentration of the second nonionic surfactant in the second solution are both 0.001-0.1 mol/L.

### Claim 2 (depends on 1)

The preparation method according to claim 1, wherein the antioxidant is one or more of butyl hydroxyanisole, dibutyl hydroxytoluene, propyl gallate, tert-butyl hydroquinone and ascorbic acid; a concentration of the antioxidant in the first solution is 0.001-0.25 mol/L.

### Claim 3 (depends on 1)

The preparation method according to claim 1, wherein a concentration of the transition metal salt solution is 0.01-1 mol/L; an addition flow rate of the second solution is 25-50 mL/h.

### Claim 4 (depends on 1)

The preparation method according to claim 1, wherein a temperature of the vacuum drying is 100-120° C.; a duration of the vacuum drying is 12-24 h.

### Claim 5 (depends on 1)

The preparation method according to claim 1, wherein the sodium alkoxide is one or both of sodium methoxide and sodium ethoxide.

### Claim 6 (depends on 1)

The preparation method according to claim 1, wherein the alcohol solution is one or both of anhydrous methanol and anhydrous ethanol.

### Claim 7 (depends on 1)

The preparation method according to claim 1, wherein when soaking, a solid-to-liquid ratio of the precipitate to the alcohol solution is 1 g:(5-100) mL; a duration of the soaking is 0.5-2 h.

### Claim 8 (depends on 1)

The preparation method according to claim 1, wherein a concentration of the sodium alkoxide in the alcohol solution is 0.05-0.5 mol/L.

### Claim 9 (depends on 1)

The preparation method according to claim 1, further comprising washing the precipitate obtained by the filtration with anhydrous methanol before the evaporation to dryness.