US-20260125369-A1 - POLYCYCLIC COMPOUND AND METHOD FOR PREPARING THE SAME, USE, ELECTROLYTE, AND BATTERY

US20260125369A1US 20260125369 A1US20260125369 A1US 20260125369A1US-20260125369-A1

Abstract

Provided are a polycyclic compound and a method for preparing the same, use, an electrolyte, and a battery. The polycyclic compound includes a compound represented by Formula I. In the compound represented by Formula I, a content of a cis-isomer represented by Formula II is greater than or equal to 98 wt %, R 1 and R 2 are each independently selected from any one of H, F, alkyl, or fluoroalkyl.

Inventors

Chaojun FAN
Weizhen FAN
Litao Shi

Assignees

GUANGZHOU TINCI MATERIALS TECHNOLOGY CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20251231
Priority Date: 20240708

Claims (13)

1 . A polycyclic compound, comprising: a compound represented by Formula I, wherein in the compound represented by Formula I, a content of a cis-isomer represented by Formula II is greater than or equal to 98 wt %, wherein R 1 and R 2 are each independently selected from any one of H, F, alkyl, or fluoroalkyl.
2 . The polycyclic compound according to claim 1 , satisfying at least one of the following conditions: (i) the polycyclic compound further comprises a chlorine-containing organic compound, wherein based on a mass of the polycyclic compound, a total content of the chlorine-containing organic compound is less than or equal to 300 ppm; (ii) the polycyclic compound further comprises other organic compounds being selected from one or more of the following 6 compounds: wherein based on the mass of the polycyclic compound, a total content of the other organic compounds is less than or equal to 1000 ppm; (iii) based on the mass of the polycyclic compound, a content of the compound represented by Formula I is greater than or equal to 99 wt %; (iv) in the compound represented by Formula I, the content of the cis-isomer represented by Formula II is greater than or equal to 98.9 wt %; (v) the compound represented by Formula I further comprises a trans-isomer represented by Formula III, wherein in the compound represented by Formula I, a content of the trans-isomer represented by Formula III is less than or equal to 1%, or (vi) R 1 and R 2 are each independently selected from any one of H, F, or fluoromethyl.
3 . The polycyclic compound according to claim 2 , satisfying at least one of the following conditions: (a) the chlorine-containing organic compound comprises a chlorine-containing organic compound without cyclic sulfate groups and cyclic carbonate groups, a chlorine-containing organic compound containing only cyclic carbonate groups, a chlorine-containing organic compound containing only cyclic sulfate groups, or a chlorine-containing organic compound containing 1 to 2 cyclic carbonate groups and 1 cyclic sulfate group; (b) based on the mass of the polycyclic compound, the total content of the chlorine-containing organic compound is less than or equal to 100 ppm; (c) based on the mass of the polycyclic compound, the total content of the other organic compounds is less than or equal to 200 ppm; (d) based on the mass of the polycyclic compound, the content of the compound represented by Formula I is greater than or equal to 99.9 wt %; or (e) in the compound represented by Formula I, the content of the trans-isomer represented by Formula III is less than or equal to 0.5 wt %.
4 . The polycyclic compound according to claim 2 , satisfying at least one of the following conditions: (α) the chlorine-containing organic compound comprises one or more of (β) based on the mass of the polycyclic compound, the total content of the chlorine-containing organic compound is less than or equal to 50 ppm; (γ) in the compound represented by Formula I, the content of the cis-isomer represented by Formula II is greater than or equal to 99.9 wt %; (δ) in the compound represented by Formula I, the content of the trans-isomer represented by Formula III is less than or equal to 0.1%; (ε) the compound represented by Formula I comprises and the compound represented by Formula II comprises (ζ) in the compound represented by Formula I, the content of the trans-isomer represented by Formula III is greater than or equal to 0.01 wt %; or (η) in the compound represented by Formula I, the content of the cis-isomer represented by Formula II is less than or equal to 99.99 wt %.
5 . A method for preparing a polycyclic compound, the method comprising: (1) mixing a hexahydric alcohol, a monohydric alcohol, a carbonate, and a basic catalyst, and performing a transesterification reaction, to obtain a compound 1; (2) dissolving the compound 1 in a solvent, and performing a condensation reaction with thionyl chloride, to obtain a compound 2; and (3) reacting the compound 2 with an oxidizing agent, to obtain a compound represented by Formula I, wherein: structural formulas of the compound 1 and the compound 2 are represented by respectively, the hexahydric alcohol comprises and a mass percentage of in the hexahydric alcohol is less than or equal to 2%, where R 1 and R 2 are each independently selected from any one of H, F, alkyl, or fluoroalkyl, and the compound represented by Formula I is
6 . The method according to claim 5 , wherein said mixing the hexahydric alcohol, the monohydric alcohol, the carbonate, and the basic catalyst, and performing the transesterification reaction satisfies at least one of the following conditions: (A) subsequent to completion of the transesterification reaction, the method further comprises: performing a reduced-pressure treatment to remove a low-boiling component; (B) the transesterification reaction is performed at a temperature ranging from 65° C. to 100° C. under a pressure controlled to be less than or equal to 2.5 MP for 0.5 hours to 6 hours; (C) a molar ratio of the carbonate to the hexahydric alcohol ranges from 3:1 to 5:1; (D) a molar ratio of the monohydric alcohol to the hexahydric alcohol ranges from 10:1 to 20:1; (E) based on a mass of the hexahydric alcohol, an amount of the basic catalyst ranges from 0.01 wt % to 5 wt %; (F) the carbonate comprises one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, or diphenyl carbonate; (G) the monohydric alcohol comprises one or more of methanol, ethanol, propanol, isopropanol, butanol, or tert-butanol; (H) the basic catalyst comprises one or more of sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate, lithium carbonate, sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert-butoxide, triethylamine, or pyridine; (I) a mass percentage of in the hexahydric alcohol is less than or equal to 1%; or (J) the mass percentage of in the hexahydric alcohol is greater than or equal to 0.01%.
7 . The method according to claim 5 , satisfying at least one of the following conditions: (I) in the step (2), subsequent to completion of the condensation reaction, the method further comprises: performing a reflux deacidification treatment, optionally, a temperature of the reflux deacidification treatment ranges from 40° C. to 80° C.; and/or a duration of the reflux deacidification treatment ranges from 10 minutes to 50 minutes; (II) in the step (2), subsequent to dissolving the compound 1 in the solvent, the condensation reaction is performed by adding thionyl chloride dropwise; (III) in the step (2), the condensation reaction is performed at a temperature ranging from 20° C. to 100° C. for 1 hour to 4 hours; (IV) in the step (2), a molar ratio of the compound 1 to the thionyl chloride is 1:(2 to 3), and an addition duration for the thionyl chloride ranges from 0.5 hours to 2 hours; (V) in the step (2), the solvent comprises one or more of an ether solvent, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, or an ester solvent; or (VI) in the step (3), the oxidizing agent is provided as an aqueous solution, and subsequent to reacting the compound 2 with the oxidizing agent, the method further comprises: performing a heating treatment on a reaction product to remove water.
8 . The method according to claim 5 , wherein said mixing the hexahydric alcohol, the monohydric alcohol, the carbonate, and the basic catalyst, and performing the transesterification reaction satisfies at least one of the following conditions: 1) the transesterification reaction is performed at a temperature ranging from 70° C. to 90° C. and a pressure ranging from 0.5 MPa to 2.2 MPa; 2) a molar ratio of the monohydric alcohol to the hexahydric alcohol ranges from 12:1 to 18:1; 3) based on a mass of the hexahydric alcohol, an amount of the basic catalyst ranges from 0.02 wt % to 0.5 wt %; or 4) the mass percentage of in the hexahydric alcohol is less than or equal to 0.5%.
9 . The method according to claim 5 , wherein said mixing the hexahydric alcohol, the monohydric alcohol, the carbonate, and the basic catalyst, and performing the transesterification reaction satisfies at least one of the following conditions: (1) the transesterification reaction is performed at a temperature ranging from 75° C. to 85° C. and a pressure ranging from 1 MPa to 2 MPa; (2) a molar ratio of the monohydric alcohol to the hexahydric alcohol ranges from 14:1 to 16:1; and (3) based on a mass of the hexahydric alcohol, an amount of the basic catalyst ranges from 0.02 wt % to 0.1 wt %; or (4) the mass percentage of in the hexahydric alcohol is less than or equal to 0.1%.
10 . A polycyclic compound prepared by the method according to claim 5 , the polycyclic compound comprising: the compound represented by Formula I, wherein in the compound represented by Formula I, a content of a cis-isomer represented by Formula II is greater than or equal to 98 wt %, and the cis-isomer represented by Formula II is
11 . An electrolyte, comprising an electrolyte additive, wherein the electrolyte additive comprises: the polycyclic compound according to claim 1 .
12 . The electrolyte according to claim 11 , wherein based on a total mass of the electrolyte, a content of the electrolyte additive ranges from 0.1 wt % to 5 wt %.
13 . A battery, comprising the electrolyte according to claim 12 .

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation of International Application No. PCT/CN2025/104817, filed on Jun. 27, 2025, which claims priority to Chinese patent application No. 202410906445X, titled “POLYCYCLIC COMPOUND AND METHOD FOR PREPARING THE SAME, USE, ELECTROLYTE, AND BATTERY”, filed with China National Intellectual Property Administration on Jul. 8, 2024, the entire contents of which are incorporated herein by reference. FIELD The present disclosure belongs to the field of a battery, and more particularly, to a polycyclic compound and a method for preparing the same, use, an electrolyte, and a battery. BACKGROUND With the rapid development of markets such as an electronic device, an electric vehicle, smart home, a power tool, and intelligent transportation, a demand for a battery is continuously increasing. Taking a lithium-ion battery as an example, the lithium-ion battery is widely used in consumer electronics, energy storage and power batteries, the smart home, and other fields due to advantages of high specific energy, long cycle life, and low self-discharge thereof. Generally, the battery consists of a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte. The electrolyte usually includes a solvent, an electrolyte lithium salt, and an electrolyte additive. Performance of the battery can be improved by adding the electrolyte additive to the electrolyte. Selecting an appropriate additive has an important impact on exertion of electrochemical performance of the battery. SUMMARY The present disclosure aims to solve one of the technical problems in the related art to some extent. The technical solution of the present disclosure is completed by the inventor based on the following findings. Currently, with increasing requirements for battery endurance and a further increase in a cost pressure of a battery cell, selection of a transition metal in a positive electrode active material becomes a mainstream development direction. For example, NCM (lithium nickel cobalt manganese oxide), LNMO (lithium nickel manganese oxide), or LMFP (lithium manganese iron phosphate) begin to develop continuously in the fields of power and energy storage. However, these materials all have a common problem: with the progress of cycling, due to intrinsic stability of the material itself or an influence of an acidic component in the electrolyte, transition metal dissolution may occur. On the one hand, the dissolved transition metal may lead to structural collapse and capacity fading of a positive electrode material. On the other hand, the dissolved transition metal may also catalyze an electrolyte reaction, resulting in high-temperature gas generation and poor interface stability. As an important component of a lithium secondary battery, the electrolyte has an important impact on comprehensive performance of the battery. An additive is an important component of the electrolyte. A suitable additive can significantly improve electrochemical performance of the battery. Therefore, it is of great importance to select the suitable additive for reducing a negative impact of the transition metal on the electrochemical performance of the battery. It was found by the inventor that applying a compound represented by Formula I as the additive to a lithium-ion battery electrolyte has a good effect on improving the electrochemical performance of the battery. Specifically, not only formation of a dense CEI film on the positive electrode and a dense SEI film on the negative electrode can be facilitated, but also a small amount of inorganic salts (taking the lithium-ion battery as an example, the inorganic salts include Li2SO4 and/or Li2O) may be formed in the CEI film formed by decomposition of the positive electrode. In this way, rigidity and flexibility of a positive electrode interface layer can be improved, inhibiting electrolyte decomposition, and enhancing stability of a positive electrode interface film. In addition, the CEI film formed by the compound represented by Formula I can also reduce electrochemical impedance of the positive electrode, accelerate a transport rate of active ions (such as Li). Also, forming a more stable electrode-electrolyte interface can be facilitated, reducing internal resistance and an interface reaction of the battery, and achieving protection for the positive electrode. Further, dissolution of transition metal ions from an active material of a positive electrode sheet can also be inhibited, reducing cyclic capacity fading of the battery, and improving cycling stability. Moreover, lithium carbonate may be generated in the SEI film formed by the compound represented by Formula I on the negative electrode. The lithium carbonate helps to improve film-forming uniformity and stability of the SEI film. In addition, the compound represented by Formula I has low impedance, which is also conducive to reducing battery impedance. However, based on a conve