EP-4741372-A1 - USE OF ADDITIVE, FORMAMIDINIUM IODIDE AND PREPARATION METHOD THEREFOR, PEROVSKITE SOLAR CELL, SOLAR POWER GENERATION DEVICE, AND ELECTRIC DEVICE

Abstract

The present application discloses a use of an additive, formamidinium iodide and a preparation method therefor, a perovskite solar cell, a solar power generation device, and an electric device. The additive comprises a reducing agent. By incorporating the reducing agent in the additive and using the additive to prepare formamidinium iodide, generation of elemental iodine in the preparation process of formamidinium iodide can be reduced; in addition, iodine which has been oxidized to elemental iodine can be reduced to iodine anions so as to generate formamidinium iodide. The stability of formamidinium iodide is improved, and thus the stability and efficiency of perovskite cells are improved.

Inventors

• LUAN, Bo
• Liang, WeiFeng
• SHI, Ruoxuan
• CHANG, Yuhang
• GUO, YONGSHENG
• CHEN, GUODONG

Assignees

• Contemporary Amperex Technology Co., Limited

Dates

Publication Date

20260513

Application Date

20240628

Claims (15)

1. Use of an additive in preparation of formamidinium iodide, the additive comprising a reducing agent.
2. The use of an additive in preparation of formamidinium iodide according to claim 1, wherein the reducing agent comprises a compound containing at least one of elements N, O, S and P.
3. The use of an additive in preparation of formamidinium iodide according to claim 2, wherein the reducing agent comprises at least one of hypophosphorous acid, red phosphorus, sulfurous acid, L-ascorbic acid, sodium thiosulfate, sodium hypophosphite, oxalic acid, hydrosulfuric acid and formamidinium sulfinic acid.
4. A preparation method for formamidinium iodide, using the additive according to any one of claims 1 to 3.
5. The preparation method for formamidinium iodide according to claim 4, comprising the following steps: mixing hydroiodic acid with the additive, cooling and storing to obtain a hydroiodic acid pretreatment solution; and mixing a formamidinium acetate solution with the hydroiodic acid pretreatment solution, crystallizing, washing and drying to obtain formamidinium iodide.
6. The preparation method for formamidinium iodide according to claim 5, wherein: the mass ratio of the additive in the hydroiodic acid pretreatment solution is 0.1%-10%; and optionally, the mass ratio of the additive in the hydroiodic acid pretreatment solution is 0.5%-5%.
7. The preparation method for formamidinium iodide according to claim 5 or 6, wherein: the cooling and storing temperature is 0-10°C; optionally, the cooling and storing temperature is 0-5°C; and/or, the cooling and storing time is 24-72 h; and optionally, the cooling and storing time is 36-60 h.
8. The preparation method for formamidinium iodide according to any one of claims 5 to 7, wherein in the step of mixing the formamidinium acetate solution with the hydroiodic acid pretreatment solution, the ratio of the amount of substance of formamidinium acetate to hydroiodic acid is 1: (0.9-1.2); and optionally, the ratio of the amount of substance of formamidinium acetate to hydroiodic acid is 1: (1.05-1.1).
9. The preparation method for formamidinium iodide according to any one of claims 5 to 8, wherein in the step of mixing the formamidinium acetate solution with the hydroiodic acid pretreatment solution, the mixing temperature is 0-35°C; optionally, the mixing temperature is 0-5°C; and/or, the mixing time is 2-8 h; optionally, the mixing time is 3-5 h; and/or, the crystallization temperature is 0-35°C; optionally, the crystallization temperature is 0-10°C; and/or, the drying mode comprises vacuum drying, in which, the drying pressure is 0 bar to -1 bar; optionally, the drying pressure is -0.8 bar to -1 bar; and/or, the drying temperature is 40-80°C; optionally, the drying temperature is 60-70°C; and/or, the drying time is 6-15 h; and optionally, the drying time is 8-12 h.
10. The preparation method for formamidinium iodide according to any one of claims 5 to 9, wherein the step of mixing the formamidinium acetate solution with the hydroiodic acid pretreatment solution, crystallizing, washing and drying to obtain formamidinium iodide comprises: mixing the formamidinium acetate solution with the hydroiodic acid pretreatment solution to obtain a mixed solution; evaporating the mixed solution, and removing the solvent to obtain a formamidinium iodide crude extract; and mixing the formamidinium iodide crude extract with a solvent, heating, recrystallizing, washing and drying to obtain formamidinium iodide.
11. The preparation method for formamidinium iodide according to claim 10, wherein: the solvent comprises ethanol; and/or, the heating temperature is 30-70°C; optionally, the heating temperature is 40-50°C; and/or, the recrystallization temperature is 0-35°C; and optionally, the recrystallization temperature is 0-5°C.
12. Formamidinium iodide, being prepared by the preparation method for formamidinium iodide according to any one of claims 4 to 11.
13. A perovskite solar cell, comprising formamidinium iodide according to claim 12.
14. A solar power generation apparatus, comprising the perovskite solar cell according to claim 13.
15. An electrical apparatus, comprising the solar power generation apparatus according to claim 14.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to Chinese Patent Application No. 202310812876.5, filed with the China Patent Office on July 04, 2023 and entitled "APPLICATION OF ADDITIVE, FORMAMIDINIUM IODIDE AND PREPARATION METHOD THEREFOR, PEROVSKITE SOLAR CELL, SOLAR POWER GENERATION APPARATUS, AND ELECTRICAL APPARATUS", which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present application relates to the technical field of batteries, and specifically relates to application of an additive, formamidinium iodide and a preparation method therefor, a perovskite solar cell, a solar power generation apparatus, and an electrical apparatus. BACKGROUND Formamidinium iodide is one of the important raw materials for perovskite solar cells. With the development of the perovskite solar cells, the demand for formamidinium iodide will continue to increase. In current preparation process, bulk-produced formamidinium iodide products have iodine precipitation and surface yellowing, and the color deepens as the storage time increases. Iodine precipitated from formamidinium iodide will be treated as a carrier recombination center in subsequent preparation of formamidinium iodide perovskite films, thereby reducing the stability and efficiency of the perovskite solar cells. SUMMARY OF THE INVENTION The present application is proposed in view of the above problems, and provides application of an additive in preparation of formamidinium iodide, aiming to reduce the precipitation of elemental iodine in a preparation process of formamidinium iodide, thereby improving the stability and efficiency of a perovskite cell. In order to achieve the above purpose, the embodiments of the present application provide application of an additive, formamidinium iodide and a preparation method therefor, a perovskite solar cell, a solar power generation apparatus, and an electrical apparatus. In a first aspect, the embodiment of the present application provides the application of the additive in preparation of formamidinium iodide, and the additive includes a reducing agent. According to the technical solution in the embodiment of the present application, by incorporating the reducing agent in the additive and using the additive to prepare formamidinium iodide, the generation of elemental iodine in the preparation process of formamidinium iodide can be reduced; in addition, iodine which is oxidized to elemental iodine can be reduced to iodine anions so as to generate formamidinium iodide, therefore, the stability of formamidinium iodide is improved, and then the stability and efficiency of the perovskite cell are improved. In any embodiment, the reducing agent includes a compound containing at least one of elements N, O, S and P. When the reducing agent including the compound containing at least one of elements N, O, S and P is used for preparing formamidinium iodide, the generation of the elemental iodine in the preparation process of formamidinium iodide can be reduced, and moreover, iodine which is oxidized to elemental iodine can be reduced to iodine anions so as to generate formamidinium iodide, therefore, the stability of formamidinium iodide is improved; moreover, when the prepared formamidinium iodide is applied to the perovskite cell, in a perovskite precursor solution, and in the presence of the reducing agent including the compound containing at least one of elements N, O, S and P, the reducing agent will be complexed with iodide, thus the solvent will be quickly removed, perovskite can be quickly nucleated and slowly crystallized, and then the stability and efficiency of the perovskite cell are further improved. In absence of the reducing agent including the compound containing at least one of elements N, O, S and P, iodide will be complexed with DMSO in the solvent, so that the crystallization rate of perovskite is increased, which does not facilitate nucleation and solvent volatilization. In any embodiment, the reducing agent includes at least one of hypophosphorous acid, red phosphorus, sulfurous acid, L-ascorbic acid, sodium thiosulfate, sodium hypophosphite, oxalic acid, hydrosulfuric acid and formamidinium sulfinic acid. By using at least one of the reducing agents, the precipitation of elemental iodine in the preparation process of formamidinium iodide can be further reduced, thus the perovskite nucleation rate is increased, the perovskite crystallization rate is decreased, the solvent volatilization rate is increased, and then the stability and efficiency of the perovskite cell are improved. In some embodiments of the present application, the reducing agent can only include one of hypophosphorous acid, red phosphorus, sulfurous acid, L-ascorbic acid, sodium thiosulfate, sodium hypophosphite, oxalic acid, hydrosulfuric acid and formamidinium sulfinic acid, and in other embodiments of the present application, two or more of them can be included at the same time. In a s