Electrode and preparation method therefor, and battery and use thereof

Abstract

An electrode (10) of a battery comprises a current collector (11) and active layers (12) bonded to the current collector (11), each active layer (12) contains an SEI film-forming additive, and the SEI film-forming additive comprises an unsaturated organic matter. By adding the SEI film-forming additives to the active layers (12) contained in the electrode (10), a stable artificial SEI film is formed in the first charging and discharging process of the battery or before the first charging and discharging, so as to effectively reduce the amount of organic components and lithium ions in an electrolyte solution consumed in the charging and discharging process of the battery, and effectively reduce the irreversible capacity of the battery, thereby significantly improving the initial coulombic efficiency and the cycle performance of the battery. The SEI film-forming additives and electrode active materials are directly prepared into an electrode slurry to prepare the electrode (10), so that the electrode (10) is high in preparation efficiency and stable in quality.

Description

Electrode and preparation method thereof, battery and battery application

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 14, 2023, with application number 202310864130.9 and application name “Electrode and preparation method thereof, battery and battery application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of battery technology, and specifically relates to an electrode and a preparation method thereof, a battery, and battery applications. Background Art

[0003] Lithium-ion batteries, due to their high energy density and low self-discharge, are rapidly gaining popularity in automotive power supplies, consumer electronics, and energy storage devices. As lithium-ion battery applications become more widespread, their electrochemical properties, such as energy density, are receiving increasing attention.

[0004] During the charge and discharge process of ion batteries, the electrolyte undergoes a reduction reaction on the negative electrode surface, producing a large amount of organic or inorganic products that are deposited on the negative electrode surface, forming a dense passivation film. However, the formation and repair of the passivation film consumes some lithium ions, resulting in an increase in irreversible capacity, a decrease in the initial coulombic efficiency of the electrode material, and a reduction in the cycle performance of the ion battery. Although existing methods have made some attempts to address this, these methods have only limited improvements in the initial coulombic efficiency and cycle performance of the battery.

[0005] Summary of the Invention

[0006] In view of the above problems, the present application provides an electrode and a preparation method thereof, a battery and a battery application to solve the technical problem that the existing solutions have limited improvement on the decrease in energy density of the battery due to the formation and repair of the passivation film.

[0007] The technology that prevents the binder in the electrode active layer contained in the sheet from floating up and causing the performance of the electrode sheet and battery to deteriorate.

[0008] In a first aspect, embodiments of the present application provide an electrode. The electrode of the embodiment of the present application includes a current collector and an active layer combined with the current collector, wherein the active layer contains an SEI film-forming additive, and the SEI film-forming additive includes an unsaturated organic matter.

[0009] The electrode of the embodiment of the present application adds unsaturated organic matter to the active layer contained therein, which can participate in and form a stable artificial SEI film during the first charge and discharge process of the battery or before the first charge and discharge, thereby effectively reducing the amount of organic components and lithium ions and other components in the electrolyte consumed by the battery during the charge and discharge process, effectively reducing the irreversible capacity in the battery, and thus significantly improving the first coulombic efficiency and cycle performance of the battery.

[0010] In some embodiments, the mass content of the unsaturated organic matter in the active layer is 0.2% to 3%, and optionally 0.5% to 1.5%. By controlling and adjusting the mass content of the unsaturated organic matter in the active layer, the SEI film-forming additive, specifically the unsaturated organic matter, can be enhanced to play the role described above, thereby increasing the content and stability of the artificial SEI film formed on the electrode, thereby further reducing the irreversible capacity in the battery and further improving the battery's initial coulombic efficiency and cycle performance.

[0011] In some embodiments, the unsaturated organic matter includes at least one of an acid group and an acid group containing an alkaline metal ion. The presence of at least one of the acid group and the acid group containing an alkaline metal ion can effectively participate in the formation of an artificial SEI film on the electrode by the unsaturated organic matter, thereby increasing the content, stability, and growth rate of the artificial SEI film, and enhancing the bonding strength and affinity between the artificial SEI film and the active layer, such as the active material.

[0012] In an embodiment, the acid group includes at least one of a carboxylate, a sulfonate, a phosphate, and a borate.

[0013] In an embodiment, the alkaline metal ions include at least one metal ion selected from the group consisting of Li, Na, K, Cs, Rb, Ca, Mg, and Al.

[0014] These acid groups and alkaline metals can participate in the formation of an artificial SEI film on the electrode with unsaturated organic matter relatively more effectively, and further improve the content, stability and growth rate of the artificial SEI film.

[0015] In some embodiments, the unsaturated organic compound comprises at least one of the following molecular formulas (I) to (II):

[0016] R5-C≡C-R6(Ⅱ);

[0017] Among them, R1 to R6 are the same or different and include -C m H n -A x , wherein H represents a hydrogen atom, A represents at least one of an acid anhydride-containing group or an acid radical group containing an alkaline metal ion; m=0 to 3, n=0 to 6, x can be 0 or 1, and m, n, and x are not all 0 at the same time.

[0018] These unsaturated organic compounds can effectively participate in and form an artificial SEI film, and improve the stability of the artificial SEI film, thereby effectively improving the battery's initial Coulombic efficiency and cycle performance. The types of groups contained in these unsaturated organic compounds can relatively improve the affinity of the artificial SEI film with the electrode material interface in the battery, the stability of the artificial SEI film itself, and other properties, while reducing the consumption of reversible ions in the battery, and relatively improving the battery's initial Coulombic efficiency and cycle performance.

[0019] In the embodiment, the unsaturated organic matter is NH x M y ; wherein N is an organic group containing an unsaturated bond and an acid radical group, H is an ionizable hydrogen atom on the acid radical, M is an alkaline metal ion, and x and y satisfy the following relationship:

[0020] x+k×y=a, and a=1-8, 0≤x / a≤0.2; 0.8≤k×y / a≤1

[0021] The a is the total valence of the unsaturated organic matter after ionization, and the k is the valence of the alkaline metal ion.

[0022] In the embodiment, the NH x M y Including (CH2=CH-COO - )H x1 Na y1 、( - OOC-CH=CH-COO - )H x2 Mg y2 、( - OOC-CH=CH-COO - )H x3 Na y3 、( - OOC-CH=CH-COO - )H x4 Li y4 、(CH(CH3)=CH-COO - )H x5 Na y5 、( - OOC-C(C2H5)=CH-COO - )H x6 Li y6 ,( - OOC-C(CH3)=CHCH2-COO - )H x7 Li y7 、( - OOC-CH2C(COO - )=CH2)Hx8 The y8 、( - OOC-C(COO - )=CHCH3)H x9 The y9 、( - OOCCH2CH2CH2-C(COO - )=CHCH3)H x10 The y10 、( - OOC-C(CH(CH3)CH2COO - )=CHCH3)H x11 The y11 、( - OOC-C(C2H5)=C(CH2CH2CH3)CH2CH2-COO - )H x12 The y12 、(HC≡C-COO - )H x13 The y13 、( - OOC-C≡C-COO - )H x14 The y14 、( - OOCCH2C≡C-COO - )H x15 The y15 、( - OOC-C≡CCH(CH3)CH2-COO - )H x16 The y16 、(CH2=CH-SO3 - )H x17 The y17 、( - O3S-CH=CH-SO3 - )H x18 Mg y18 、( - O3S-CH=CH-SO3 - )H x19 The y19 、( - O3S-CH=CH-SO3 - )H x20 The y20 、(CH(CH3)=CH-SO3 - )H x21 The y21 、( - O3S-C(C2H5)=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x22 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y22 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(CH3) = CHCH2-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x23 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y23 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-CH2C(SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CH2)H<h2 style=";text-align:left;direction:ltr"> x24 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y24 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x25 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y25 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3SCCH2CH2CH2-C(SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x26 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y26 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(CH(CH3)CH2SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x27 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y27 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(C2H5) = C(CH2CH2CH3)CH2CH2-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x28 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y28 <h2 style=";text-align:left;direction:ltr"> (HC≡C-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x29 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y29 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C≡C-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x30 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y30 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3SCH2C≡C-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x31 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y31 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C≡CCH(CH3)CH2-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x32 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y32 <h2 style=";text-align:left;direction:ltr"> (CH2 = CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x33 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y33 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH=CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x34 <h2 style=";text-align:left;direction:ltr"> Mg<h2 style=";text-align:left;direction:ltr"> y34 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH=CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x35 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y35 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH=CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x36 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y36 <h2 style=";text-align:left;direction:ltr"> (CH(CH3) = CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x37 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y37 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C(C2H5)=CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x38 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y38 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> --2 <h2 style=";text-align:left;direction:ltr"> O3P-C(CH3) = CHCH2-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x39 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y39 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH2C(PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> )=CH2)H<h2 style=";text-align:left;direction:ltr"> x40 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y40 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C(PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x41 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y41 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH2CH2CH2-C(PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x42 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y42 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C(CH(CH3)CH2-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x43 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y43 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C(C2H5)=C(CH2CH2CH3)CH2CH2-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x44 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y44 <h2 style=";text-align:left;direction:ltr"> (HC≡C-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x45 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y45 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C≡C-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x46 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y46 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3PCH2C≡C-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x47 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y47 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C≡CCH(CH3)CH2-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x48 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y48 <h2 style=";text-align:left;direction:ltr"> (CH2+CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x49<h2 style=";text-align:left;direction:ltr">Na<h2 style=";text-align:left;direction:ltr"> y49 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-CH=CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x50 <h2 style=";text-align:left;direction:ltr"> Mg<h2 style=";text-align:left;direction:ltr"> y50 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-CH=CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x51 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y51 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-CH=CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x52 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y52 <h2 style=";text-align:left;direction:ltr"> (CH(CH3) = CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x53 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y53 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-C(C2H5)=CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x54 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y54 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-C(CH3) = CHCH2-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x55 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y55 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-CH2C(BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CH2)H<h2 style=";text-align:left;direction:ltr"> x56 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y56 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-C(BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x57 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y57 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-CH2CH2CH2-C(BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x58 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y58 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-C(CH(CH3)CH2-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x59 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y59 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-C(C2H5)=C(CH2CH2CH3)CH2CH2-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x60 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y60 <h2 style=";text-align:left;direction:ltr"> (HC≡C-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x61 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y61 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-C≡C-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x62 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y62 <h2 style=";text-align:left;direction:ltr"> 、(- HO2B-CH2C≡C-BO2H - )H x63 Li y63 、( - HO2B-C≡CCH(CH3)CH2-BO2H - )H x64 Li y64 At least one of;

[0023] Among them, x1 to x64 and y1 to y64 all satisfy: x+k×y=a, a=1-8, 0≤x / a≤0.2, 0.8≤k×y / a≤1.

[0024] In an exemplary embodiment, the unsaturated organic compound includes at least one of the unsaturated organic compounds represented by the following molecular structural formula:

[0025] ( - OOC-CH=CH-COO - )H 0.1 Na 1.9 、( - OOC-CH=CH-COO - )H 0.4 Na 1.6 、( - OOC-CH=CH-COO - )H 0.1 Li 1.9 、( - OOC-CH=CH-COO - )H 0.1 K 1.9 、( - OOC-CH=CH-COO - )H 0.1 Cs 1.9 、( - OOC-CH=CH-COO - )H 0.1 Ca 0.95 、( - OOC-CH=CH-COO - )H 0.1 Mg 0.95 、(-OOC-CH=CH-COO-)H 0.1 Al 0.63 、(CH(CH3)=CH-COO - )H 0.05 Na 0.95 、( - OOC-C(C2H5)=CH-COO - )H 0.1 Li1.9 、( - OOC-CH2C(COO - )=CH2)H 0.1 Li 1.9 、( - OOC-C(COO - )=CHCH3)H 0.1 Li 1.9 、(HC≡C-COO - )H 0.05 Li 0.95 、( - OOC-C≡C-COO - )HLi、(CH2=CH-COO - )H 0.05 Li 0.95 、(CH2=CH-SO3 - )H 0.0 5Li 0.95 、(CH2=CH-PO3 2- )HLi、(CH2=CH-BO2H - )H 0.05 Li 0.95 .

[0026] The above-mentioned unsaturated organic substances are all capable of effectively participating in and forming an artificial SEI film, and improving the content and stability of the artificial SEI film and the affinity with the active layer such as the active material, thereby effectively improving the first coulombic efficiency and cycle performance of the battery.

[0027] In some embodiments, at least a portion of the unsaturated organic matter is combined with the electrode active material contained in the active layer.

[0028] In some embodiments, at least a portion of the SEI film-forming additive forms a coating layer that covers the surface of the electrode active material.

[0029] The unsaturated organic matter is combined with the electrode active material or further coated with the electrode active material. The artificial SEI film that the unsaturated organic matter can participate in forming can be directly formed on the surface of the electrode active material, or further formed into an artificial SEI film to directly coat the surface of the electrode active material, thereby improving the protective effect of the artificial SEI film on the electrode active material and improving the stability of the electrochemical performance of the electrode active material.

[0030] In some embodiments, the electrode is a cathode.

[0031] In a second aspect, the present invention provides a method for preparing an electrode. The method comprises the following steps:

[0032] The SEI film-forming additive is mixed with the active material to prepare an electrode slurry;

[0033] Forming a film of the electrode slurry on a current collector to prepare an active layer;

[0034] Wherein, the SEI film-forming additive includes unsaturated organic matter.

[0035] The electrode preparation method of the embodiment of the present application directly prepares the electrode slurry by combining the SEI film-forming additive including unsaturated organic matter with the active layer components, so that the SEI film-forming additive can be dispersed in the prepared active layer, and an artificial SEI film can be formed on the electrode. The artificial SEI film has good stability, thereby significantly improving the first coulombic efficiency and cycle performance of the battery.

[0036] In some embodiments, the pH of the electrode slurry is 6-10.5, and can be optionally 6.8-9.

[0037] By adjusting the pH of the prepared electrode slurry, the uniformity of dispersion of the components of the electrode slurry and the stability of the slurry can be improved, the floating phenomenon of the electrode slurry can be effectively reduced, the consumption of ions such as lithium ions in the electrode slurry and the side reactions in the electrode slurry can be reduced, thereby improving the processability and film-forming properties of the electrode slurry and improving the quality of the electrode active layer.

[0038] In a third aspect, the present invention provides a battery. The battery comprises the electrode of the above embodiment or an electrode prepared by the method for preparing the electrode of the above embodiment.

[0039] Since the battery of the embodiment of the present application contains the electrode of the embodiment of the present application, the battery of the embodiment of the present application has high first coulombic efficiency and good cycle performance.

[0040] In some embodiments, the electrode is a negative electrode, and a polymer formed by polymerization of the unsaturated organic matter is disposed on the negative electrode.

[0041] In this way, the battery of the embodiment of the present application has a negative electrode, and a stable artificial SEI film can be formed on the negative electrode, thereby significantly improving the initial coulombic efficiency and cycle performance of the battery.

[0042] In some embodiments, the electrolyte contained in the battery contains an initiator, and the initiator is used for the polymerization reaction of the SEI film-forming additive.

[0043] In an embodiment, the mass content of the initiator in the electrolyte is 0.01% to 1.0%, and can be optionally 0.2% to 0.6%.

[0044] In an exemplary embodiment, the initiator includes at least one of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, and benzoyl peroxide.

[0045] Adding the initiator to the electrolyte and further selecting and controlling the amount and type of the initiator can promote the polymerization reaction of the unsaturated organic SEI film-forming additive in the active layer contained in the electrode to generate an artificial SEI film and improve the generation efficiency and stability of the artificial SEI film.

[0046] In the embodiment, the battery is subjected to a heating and soaking treatment before the formation treatment.

[0047] In the embodiment, the temperature of the heating and soaking treatment is 60-80°C.

[0048] By performing a heat soaking treatment before the battery's formation process and adjusting the temperature during this process, the initiator can enhance the polymerization reaction of the unsaturated organic SEI film-forming additive contained in the electrode's active layer, thereby improving the efficiency and stability of the artificial SEI film. Within this temperature range, the heat soaking treatment should be sufficient to allow the unsaturated organic SEI film-forming additive to fully react and form an artificial SEI film.

[0049] In some embodiments, the first coulombic efficiency of the battery is greater than 80%.

[0050] In some embodiments, the cycle retention rate of the battery is above 93%.

[0051] According to tests, the battery of the embodiment of the present application has a high initial coulombic efficiency, such as higher than 80%, and a good cycle performance, which can reach more than 93%.

[0052] In a fourth aspect, the present invention further provides an electric device. The electric device of the present invention includes the battery of the above-mentioned embodiment.

[0053] The electrical device in the embodiment of the present application has a long standby or battery life.

[0054] In a fifth aspect, the present application also provides an energy storage device. The energy storage device of the present application includes the battery of the above-mentioned embodiment.

[0055] The electrical device in the embodiment of the present application has good performance and long service life.

[0056] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0058] FIG1 is a schematic diagram of the structure of an electrode in some embodiments of the present application;

[0059] FIG2 is another schematic diagram of the structure of electrodes according to some embodiments of the present application;

[0060] FIG3 is a schematic structural diagram of an embodiment of a battery cell according to the present application;

[0061] FIG4 is an exploded schematic diagram of the battery cell shown in FIG3 ;

[0062] FIG5 is a schematic structural diagram of an embodiment of a battery module according to the present application;

[0063] FIG6 is a schematic structural diagram of an embodiment of a battery pack according to the present application;

[0064] FIG7 is a schematic diagram of the exploded structure of the battery pack shown in FIG6 ;

[0065] FIG8 is a schematic diagram of an embodiment of an electrical device including a battery according to an embodiment of the present application as a power source;

[0066] The accompanying drawings in the specific implementation manner are as follows:

[0067] 10-electrode, 11-current collector, 12-active layer;

[0068] 20-battery cell, 21-housing, 22-electrode assembly, 23-cover plate;

[0069] 30-battery module;

[0070] 40-battery pack, 41-box, 42-lower box. DETAILED DESCRIPTION

[0071] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0072] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0073] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0074] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0075] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0076] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0077] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0078] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0079] With the rapid adoption of lithium batteries, particularly in electric vehicles, the requirements for initial efficiency and energy density are becoming increasingly stringent. Ion batteries contain an electrolyte. During the initial charge and discharge process, the electrode material and electrolyte react at the solid-liquid interface, generating a large amount of organic or inorganic products and forming a dense passivation layer covering the electrode surface. This passivation layer is known as the solid electrolyte interface (SEI).

[0080] Although the formation of the SEI film improves the cycle performance and service life of the electrode, it consumes some lithium ions during the formation process, resulting in an increase in the irreversible capacity of the electrode material and a reduction in the initial coulombic efficiency of the electrode material. Moreover, during the subsequent charge and discharge process of the ion battery, the SEI film is unstable and the SEI film will continue to repair. During this repair process, the lithium ions in the ion battery will continue to be consumed, thereby reducing the battery's cycle performance.

[0081] To reduce the reversible lithium ion consumption during the charge and discharge process of ion batteries, lithium-supplementing additives are generally added to the positive electrode, or the electrode material surface is modified to form an artificial SEI film to reduce the reversible lithium ion consumption and improve the SEI film. However, in actual production, it has been found that the current solutions of using lithium-supplementing additives and artificial SEI film treatment of electrode materials are still not ideal, resulting in limited improvements in the battery's initial coulombic efficiency and cycle performance.

[0082] In order to maximize the initial coulombic efficiency and cycle performance of ion batteries, a corresponding SEI film-forming additive is creatively added to the electrode active layer. The presence of this SEI film-forming additive can form an SEI film before or during the charge and discharge process of the battery, and can also effectively improve the stability of the SEI film in the battery, thereby effectively reducing the irreversible capacity of the battery to improve the initial coulombic efficiency and cycle performance of the battery. Based on the above research solution, the embodiment of this application proposes the following technical solution.

[0083] electrode

[0084] In a first aspect, embodiments of the present application provide an electrode. In some embodiments, as shown in Figures 1 and 2 , an electrode 10 according to an embodiment of the present application includes a current collector 11 and an active layer 12. The active layer 12 is bonded to the current collector 11 and contains an SEI film-forming additive, wherein the SEI film-forming additive includes an unsaturated organic compound.

[0085] In the electrode 10 of the present embodiment, the SEI film-forming additive contained in the active layer 12 refers to an organic substance that can preferentially participate in the formation of an SEI film on the electrode surface. Unsaturated organic matter refers to organic matter containing unsaturated bonds. The inclusion of the SEI film-forming additive in the active layer 12 means that the SEI film-forming additive is loaded into the active layer 12 by means including, but not limited to, doping.

[0086] Since the electrode 10 of the embodiment of the present application adds an SEI film-forming additive of unsaturated organic matter in the active layer 12 contained therein, the SEI film-forming additive of unsaturated organic matter can participate in and form an artificial SEI film during the first charge and discharge process of the battery containing the electrode 10 of the embodiment of the present application or before the first charge and discharge, specifically, the unsaturated organic matter contained in the SEI film-forming additive can open the unsaturated bonds contained therein during the first charge and discharge process of the battery or before the first charge and discharge, and at least undergo polymerization reaction with the adjacent unsaturated organic matter, or further undergo some reaction with the organic solvent, additives, etc. in the electrolyte contained in the battery, thereby forming a polymer on the active layer 12, and the polymer participates in the formation of the artificial SEI film, thereby effectively reducing the amount of organic components and lithium ions and other components in the electrolyte consumed by the battery during the charge and discharge process, thereby effectively improving the first coulombic efficiency of the battery; and the formed artificial SEI film has good stability, which reduces the probability or amount of repair of the SEI film contained in the battery during the charge and discharge process. Therefore, the electrode 10 of the embodiment of the present application can effectively reduce the irreversible capacity in the battery, thereby significantly improving the first coulombic efficiency and cycle performance of the battery.

[0087] Among them, the current collector 11 contained in the electrode 10 of the embodiment of the present application refers to a structure or part for collecting current. In the embodiment, the current collector 11 contained in the electrode 10 of the embodiment of the present application includes but is not limited to a metal current collector, a carbon current collector, a conductive resin current collector, a composite current collector of metal and resin, etc., more specifically, for example, copper, nickel, titanium, iron and their respective alloys, stainless steel, carbon fiber, carbon nanotubes (CNT), graphite, etc. In the embodiment, the current collector 11 can also be a dense film layer or a film layer with a porous structure. In the embodiment, the current collector 11 can be a positive electrode current collector or a negative electrode current collector according to the positive or negative polarity of the electrode 10 of the embodiment of the present application. When the current collector 11 is a positive electrode current collector, the current collector 11 can be but is not limited to aluminum foil or porous aluminum foil, etc. When the current collector 11 is a negative electrode current collector, the current collector 11 can be but is not limited to copper foil or porous copper foil, etc.

[0088] The active layer 12 included in the electrode 10 of the present embodiment refers to a film layer containing an electrode active material. In the embodiments, the active layer 12 included in the electrode 10 of the present embodiment is combined with the current collector 11 and can be laminated on the surface of the current collector 11. When the surface layer of the current collector 11 has a porous structure or the current collector 11 itself has a porous structure, the active layer 12 can be at least partially embedded in the current collector 11.

[0089] In an embodiment, when the active layer 12 is laminated on the surface of the current collector 11, it can be bonded to one surface of the current collector 11, as shown in Figure 1. When the current collector 11 has two opposing surfaces, that is, when it is a membrane structure, the active layer 12 can be bonded to two opposing surfaces of the current collector 11, as shown in Figure 2.

[0090] In the embodiment, the active layer 12 contained in the electrode 10 of the embodiment of the present application contains not only the above-mentioned SEI film-forming additive components, but also necessary components such as electrode active materials and other components. Other components may include binders or may further contain conductive agents, other additives and other components.

[0091] In an embodiment, when the electrode 10 of the present application is a negative electrode, the active layer 12 is a negative electrode active layer. The negative electrode active material contained in the negative electrode active layer may include one or more of a carbon-based active material, a titanium-based active material, a silicon-based active material, a nitride, metallic lithium, and the like. In exemplary embodiments, the carbon-based material may include one or more of graphite, hard carbon, soft carbon, mesocarbon microbeads, graphene, and the like; in exemplary embodiments, the titanium-based active material may include one or more of lithium titanate and titanium dioxide; in exemplary embodiments, the silicon-based active material may include one or more of silicon and silicon dioxide; and in exemplary embodiments, the nitride may include lithium nitride, and the like.

[0092] Of course, based on the structure of the electrode 10 of the above embodiment and the solution of adding SEI film-forming additive components in the active layer 12, the electrode 10 of the above embodiment can also be a positive electrode. In the embodiment, when the electrode 10 of the embodiment of the present application is a positive electrode, the active layer 12 is a positive electrode active layer, and the positive electrode active material contained in the positive electrode active layer may include one or more of metal inorganic active materials and organic active materials. In the exemplary embodiment, the metal inorganic active material may include one or more of lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium manganese oxide, nickel cobalt manganese iron lithium, nickel cobalt aluminum oxide, etc. In the exemplary embodiment, the organic active material may include one or more of quinone compounds, carboxylate compounds, acid anhydride compounds, amide compounds, etc.

[0093] In an embodiment, when the active layer 12 contains a binder, the binder may include one or more of an oil-soluble binder, a water-soluble binder, an emulsion-type binder, etc. In an exemplary embodiment, the oil-soluble binder may include one or more of polyvinylidene fluoride, polyimide, polytetrafluoroethylene, polybutyl acrylate, polyacrylonitrile, etc.; in an exemplary embodiment, the water-soluble binder may include one or more of carboxymethyl cellulose, carboxymethyl cellulose salt, polyacrylic acid, polyacrylic acid salt, polyvinyl alcohol, sodium alginate, cyclodextrin, etc.; in an exemplary embodiment, the emulsion-type binder may include one or more of styrene-butadiene rubber, vinyl acetate resin, acrylic resin, and chlorinated rubber.

[0094] In an embodiment, when the active layer 12 contains a conductive agent, the conductive agent may include one or more of acetylene black (SP), carbon nanotubes, conductive carbon black (super-P), Ketjen black, carbon fiber, graphene, and the like.

[0095] In the embodiment, when the active layer 12 contains other additives, the additives may include but are not limited to functional components such as lithium supplements.

[0096] The above-mentioned negative electrode active materials, positive electrode active materials, binders, and conductive agents can be selected according to the application or production requirements of the electrode 10. In the embodiment, based on the effect of the SEI film-forming additive in the active layer 12 contained in the electrode 10 of the embodiment of the present application, the electrode 10 of the embodiment of the present application is relatively preferred to be a negative electrode, and the current collector 11 contained therein is relatively preferred to be a negative electrode current collector, and the active layer 12 contained therein is also relatively preferred to be a negative electrode active layer.

[0097] In addition, the thickness of the active layer 12 can also be controlled according to battery performance such as energy density. For example, when the electrode 10 in each of the above embodiments is a negative electrode, the thickness of the active layer 12 in the electrode 10 can be 140-150 μm.

[0098] In the embodiments, the mass content of unsaturated organic matter in the active layer 12 of the electrodes 10 of the above-mentioned embodiments can be 0.2% to 3%, and optionally 0.5% to 1.5%. In exemplary embodiments, the mass content of the unsaturated organic matter can be in typical but non-limiting ranges such as 0.2% to 0.5%, 0.5% to 0.8%, 0.8% to 1%, 1% to 1.5%, 1.5% to 2%, 2% to 2.5%, and 2.5% to 3%. The mass content of the unsaturated organic matter refers to the percentage of the mass of the unsaturated organic matter to the total mass of the active layer 12. By controlling and adjusting the mass content of the unsaturated organic matter in the active layer 12, the role of the SEI film-forming additive, specifically the unsaturated organic matter, can be enhanced, thereby increasing the content and stability of the artificial SEI film formed by the electrode 10, thereby further reducing the irreversible capacity of the battery and further improving the initial coulombic efficiency and cycle performance of the battery. As detected, the mass content of the unsaturated organic matter in the active layer 12 is controlled within a range of 0.2% to 3%, and further within a range of 0.5% to 1.5%. Compared with other content ranges of the unsaturated organic matter in the active layer 12, the content and stability of the artificial SEI film formed on the electrode 10 can be significantly increased, thereby further reducing the irreversible capacity in the battery and further improving the initial coulombic efficiency and cycle performance of the battery.

[0099] In an embodiment, at least a portion of the unsaturated organic matter is bound to at least the electrode active material in the active layer 12. The unsaturated organic matter can be bound to a localized surface of the electrode active material. The localized surface can be one or more locations on the surface of the electrode active material, or it can be bound continuously or in an island pattern. In this way, the artificial SEI film formed with the unsaturated organic matter can be formed directly on the surface of the electrode active material, thereby enhancing the protective effect of the artificial SEI film on the electrode active material and improving the stability of the electrochemical performance of the electrode active material.

[0100] In an embodiment, at least a portion of the SEI film-forming additive forms a coating layer that coats the surface of the electrode active material. The coating layer refers to a continuous film layer formed by the SEI film-forming additive and coating the electrode active material. Since the SEI film-forming additive contains unsaturated organic matter, the content of the unsaturated organic matter can be controlled so that the unsaturated organic matter forms a coating layer that coats the electrode active material. In this way, the artificial SEI film formed by the SEI film-forming additive that forms the coating layer, such as the unsaturated organic matter, can form an artificial SEI coating layer that directly coats the surface of the electrode active material, thereby further improving the protective effect of the artificial SEI coating layer on the electrode active material, so as to further improve the stability of the electrochemical performance of the electrode active material.

[0101] In the embodiment, the unsaturated organic matter in the above embodiment includes at least one of an acid radical group and an acid radical group containing an alkaline metal ion. Among them, the acid radical group refers to the group of the acid radical ion, which can produce anions when the acid is ionized. The alkaline metal ion refers to a slightly alkaline metal cation. In the unsaturated organic matter, at least one of the acid radical group and the alkaline metal ion can effectively participate in the formation of an artificial SEI film on the active layer 12 of the electrode 10 of the unsaturated organic matter, and improve the affinity of the artificial SEI film with the active substance and provide a skeleton for the subsequent decomposition of the electrolyte into a film, thereby improving the overall structural stability of the SEI film. Among them, when the unsaturated organic matter contains alkaline metal ions, the alkaline metal ions can effectively participate in the formation of an artificial SEI film before the reversible ions in the battery, thereby reducing the battery's consumption of reversible ions in the battery during the formation of the SEI film. The reversible ions include, for example, lithium ions, and of course, sodium ions. For example, the consumption of reversible lithium ions or sodium ions in the electrode material, especially the positive electrode material, and the electrolyte is reduced, thereby reducing the irreversible capacity in the battery, and further improving the battery's first coulombic efficiency and cycle performance. When containing both acid groups and alkaline metal ions, the acid groups can also increase the content of alkaline metal ions in the unsaturated organic matter, balance the pH change after the addition of alkaline metal ions, and enhance the contribution of acid groups and alkaline metal ions to the artificial SEI film in the battery and to improving the battery's first coulombic efficiency and cycle performance.

[0102] In an exemplary embodiment, the acid group comprises a carboxylate (e.g., -COOH n1 M m1 ), sulfonate (as shown below -SO3H n2 M m2 ), phosphate (as shown below -PO3H n3 M m3 ), borate (hereinafter -BO2H n4 M m4 ). In an exemplary embodiment, the alkaline metal ions may include metal elements from Groups I to III of the periodic table, such as at least one metal ion selected from Li, Na, K, Cs, Rb, Ca, Mg, and Al. Compared to other acid groups and alkaline metals, these acid groups and alkaline metals can more effectively participate in the formation of an artificial SEI film on the electrode 10 from unsaturated organic matter, further improving the content, stability, and growth rate of the artificial SEI film. They also enhance affinity with the active layer, such as the active material, and improve the bonding strength between the artificial SEI film and the active material. These alkaline metal ions, such as lithium and sodium ions, can effectively participate in the formation of the artificial SEI film, thereby reducing the consumption of lithium and sodium ions contained in the battery. This can further reduce the irreversible capacity of the battery, thereby further improving the initial coulombic efficiency and cycling performance of the battery.

[0103] Based on the unsaturated organic matter in the above embodiments, such as the content of the unsaturated organic matter in the active layer 12 and the presence of acid groups, alkaline metal ions, and other groups or metal ions, in some embodiments, the unsaturated organic matter includes at least one of the following molecular formulas (I) to (II):

[0104] (Ⅰ) R5-C≡C-R6;

[0105] The organic substances represented by molecular formulas (I) to (II) all contain unsaturated chemical bonds, and the unsaturated bonds contained therein can be effectively opened, that is, broken, during the first charge and discharge process of the battery or before the first charge and discharge, and can at least undergo polymerization reactions with adjacent unsaturated organic substances, or further react with organic solvents, additives, etc. in the electrolyte contained in the battery, thereby forming a polymer film layer on the active layer 12 of the electrode 10. These unsaturated organic substances can effectively participate in and form an artificial SEI film, and improve the stability of the artificial SEI film, thereby effectively improving the first coulombic efficiency and cycle performance of the battery.

[0106] In the embodiment, when the unsaturated organic compound contains the unsaturated organic compound represented by the molecular formula (I), R1 to R4 of the molecular formula (I) are the same or different and include -C m H n -A x , wherein H represents a hydrogen atom, A represents at least one of an acid anhydride-containing group or an acid radical group containing an alkaline metal ion; m = 0 to 3, in which examples, m can be 0, 1, 2, 3, etc.; n = 0 to 6, in which examples, n can be 0, 1, 2, 3, 4, 5, 6, etc.; x = 0 to 1, in which examples, x can be 0 or 1. In addition, m, n, and x cannot all be 0.

[0107] Based on -C m H n -A x and the values ​​of m, n, and x, the -C m H n -A x At least the group type shown in the following examples can be:

[0108] In the embodiment, when m=0, x=0, and n≠0, then -C m H n -A x It is a hydrogen atom, that is, -H.

[0109] In the embodiment, when m=0 and x≠0, then -C m H n -A x Actually contains -Ax At least one of an acid group containing an acid radical and an acid radical group containing an alkaline metal ion.

[0110] In the embodiment, when m≠0 and x=0, then -C m H n -A x Actually contains -C m H n of an alkyl group.

[0111] In the embodiment, when m≠0 and x≠0, then -C m H n -A x The alkyl group is at least one of an acid group containing an acid group and an acid group containing an alkaline metal ion.

[0112] Among them, at least one of the acid radical group and the acid radical group containing alkaline metal ions in the above embodiments can be a group containing only acid radicals or an acid radical group containing alkaline metal ions, or can be a group containing both acid radicals and an acid radical group containing alkaline metal ions.

[0113] In the example, when m≠0 in the above embodiment (x≠0 or x=0), that is, m H n When the above-C m H n It may include one or more of -CH3, -CH2CH3, -CH(CH3)CH3, -CH2CH2CH3, -CH2-, -CH(CH3)-, -CH2CH2-, -CH2CH2CH2-, -C(CH3)2-, -CH2CH(CH3)-, and -CH(CH3)CH2-.

[0114] In the example, when x≠0 in the above embodiment (m≠0 or m=0), that is, when A is contained, A is at least one of an acid anhydride-containing group or an acid radical group containing an alkaline metal ion. For example, in the embodiment, A includes -COOH n1 M m1 、-SO3H n2 M m2 、-PO3H n3 M m3 、-BO2H n4 M m4One or more of. Wherein, M represents the above-mentioned alkaline metal ion, m1 to m4 respectively represent the number of atoms of M, and n1 to n4 respectively represent the number of atoms of H; and n1 to n4 are the same or different ≥ 0, m1 to m4 are the same or different ≥ 0, but at least one of n1 to n4 and at least one of m1 to m4 are not 0 at the same time; the product of the number of n hydrogen (H) elements and the valence of hydrogen ions + the product of m alkaline metal ions (M) and the valence of alkaline metal ions is equal to the total valence of the acid radical groups contained in A after ionization. Based on this, -COOH n1 M m1 Including -COOH (n1 equals 1, m1 equals 0), -COOM (n1 equals 0, m1 equals 1, the valence of M equals 1); -SO3H n2 M m2 Including -SO3M (n2 equals 0, m2 equals 1, M valence equals 2); -PO3H n3 M m32 Including -PO3M (n3 equals 0, m3 equals 1, the valence of M equals 2), -PO3HM (n3 = m3 = 1, and the sum of the valences of 1 + M equals 2); -BO2H n4 M m4 It includes one or more of -BO2HM (n4=m4=1, the sum of the valence states of 1+M is equal to 2), -BO2M (n4=0, m4=1, the valence state of M is equal to 2).

[0115] In the example, when m≠0, x≠0 in the above embodiment, then -C m H n -A x -C in m H n and -A x Can be the above-C m H n The groups shown and -A x Combinations of groups or ions shown.

[0116] In the embodiment, when the unsaturated organic compound contains the unsaturated organic compound represented by the molecular formula (II), R5 to R6 are the same as R1 to R4 in the above molecular formula (I), and the same or different compounds include -C m H n -A x The -C m H n -A x The specific groups shown are the same as the scope and group types explained above for R1 to R4, and will not be repeated here to save space.

[0117] When the groups represented by R1 to R6 above are especially non-hydrogen groups, after the above unsaturated organic matter is used as a raw material to participate in the generation of an artificial SEI film, in the generated artificial SEI film, the groups represented by R1 to R6 can play the role of a skeleton of the artificial SEI film, thereby enhancing the stability of the artificial SEI film, reducing the amount of repair of the battery during the charge and discharge process, and further reducing the irreversible capacity of the battery, thereby improving the first coulombic efficiency and cycle performance of the battery. When the groups represented by R1 to R4 contain at least one of an acid group and an acid group containing an alkaline metal ion, these acid groups and alkaline metal ions can participate in the formation of an artificial SEI film and increase the content, stability, and growth rate of the artificial SEI film. The alkaline metal ions contained participate in the formation of the artificial SEI film and reduce the consumption of lithium, sodium, and other ions contained in the battery, thereby further reducing the irreversible capacity of the battery and further improving the battery's initial coulombic efficiency and cycle performance. The acid group can enhance the affinity between the generated artificial SEI film and the active layer, such as the active material, and improve the bonding strength between the artificial SEI film and the active material. Therefore, compared to unsaturated organic compounds that do not contain acid groups, alkaline metal ions, etc., the unsaturated organic compounds containing the above R1 to R6 can relatively increase the content, stability, and other properties of the artificial SEI film in the battery, and relatively improve the battery's initial coulombic efficiency and cycle performance.

[0118] When the unsaturated organic matter contained in the active layer 12 of the electrode 10 in each of the above embodiments contains at least one of an acid radical group and an acid radical group containing an alkaline metal ion, in the embodiment, the unsaturated organic matter can be represented by NH x M y In the NH x M y The x and y in the equation satisfy the following relationship:

[0119] x+k×y=a, a=1-8, can be 1-4, 1-2, and 0≤x / a≤0.2, 0.8≤k×y / a≤1.

[0120] Among them, NH x M y N is an organic group containing an unsaturated bond and an acid radical group. The number of acid radical groups contained in the organic group N can be 1 to 8, further can be 1 to 4, 1 to 2, and in exemplary embodiments, can be 1, 2, 3, 4, 5, 6, 7, 8, etc.; H is the hydrogen ion of the ionized acid radical group in N, M is an alkaline metal ion, a is the total valence state of the acid radical group in N after ionization, and k is the valence state of the alkaline metal ion represented by M.

[0121] Then x+k×y=a means that in unsaturated organic matter, the total valence of the acid radical group contained in the organic group N after ionization is equal to the sum of the valence of the contained H ion multiplied by the molar amount of H ion and the valence of the alkaline metal ion indicated by M multiplied by the molar amount of the alkaline metal ion; if NH x M y When the unsaturated organic matter shown contains multiple alkaline metal ions, a=x+k1×y1+...+kn×yn, wherein n represents the number of multiple alkaline metal ions.

[0122] 0≤x / a≤0.2 means NH x M y The quotient of the total molar amount of ionizable hydrogen ions of the acid radical groups in the N of the unsaturated organic compound and the total valence state after ionization of the acid radical groups in the N is greater than or equal to 0 and less than or equal to 0.2.

[0123] 0.8≤k×y / a≤1 means NH x M y The quotient of the product of the valence of the alkaline metal ion represented by M in the unsaturated organic matter and the mole of the alkaline metal ion and the total valence of the acid radical group in N after ionization is greater than or equal to 0.8 and less than or equal to 1.

[0124] Based on NH x M y In the example shown in the unsaturated organic matter, when NH x M y When the organic group N contains a carboxylate, the NH x M y At least one of the unsaturated organic compounds shown in the following molecular formulas may be included:

[0125] (CH2=CH-COO - )H x1 Na y1 、( - OOC-CH=CH-COO - )H x2 Mg y2 、( - OOC-CH=CH-COO - )H x3 Na y3 、( - OOC-CH=CH-COO - )H x4 Li y4 、(CH(CH3)=CH-COO - )H x5 Na y5 、( - OOC-C(C2H5)=CH-COO- )H x6 Li y6 ,( - OOC-C(CH3)=CHCH2-COO - )H x7 Li y7 、( - OOC-CH2C(COO - )=CH2)H x8 Li y8 、( - OOC-C(COO - )=CHCH3)H x9 Li y9 、( - OOCCH2CH2CH2-C(COO - )=CHCH3)H x10 Li y10 、( - OOC-C(CH(CH3)CH2COO - )=CHCH3)H x11 Li y11 、( - OOC-C(C2H5)=C(CH2CH2CH3)CH2CH2-COO - )H x12 Li y12 、(HC≡C-COO - )H x13 Li y13 、( - OOC-C≡C-COO - )H x14 Li y14 、( - OOCCH2C≡C-COO - )H x15 Li y15 、( - OOC-C≡CCH(CH3)CH2-COO - )H x16 Li y16 .

[0126] Among them, the carboxyl anhydride in these compounds can be replaced by other anhydrides, such as -SO3 - 、-PO3H - 、-PO3 2- In the embodiment, when the carboxyl anhydride contained in the above compound is replaced by -SO3 - When substituted, containing -SO3 - The compound includes at least one of the following compounds:<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0127] <h2 style=";text-align:left;direction:ltr"> (CH2=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x17 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y17 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-CH=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x18 <h2 style=";text-align:left;direction:ltr"> Mg<h2 style=";text-align:left;direction:ltr"> y18 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-CH=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x19 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y19 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-CH=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x20 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y20 <h2 style=";text-align:left;direction:ltr"> (CH(CH3) = CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x21 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y21 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(C2H5)=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x22 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y22 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(CH3) = CHCH2-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x23 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y23 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-CH2C(SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CH2)H<h2 style=";text-align:left;direction:ltr"> x24 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y24 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x25 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y25 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3SCCH2CH2CH2-C(SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x26 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y26 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(CH(CH3)CH2SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x27 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y27 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(C2H5) = C(CH2CH2CH3)CH2CH2-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x28 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y28 <h2 style=";text-align:left;direction:ltr"> (HC≡C-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x29 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y29 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C≡C-SO3- )H x30 Li y30 、( - O3SCH2C≡C-SO3 - )H x31 Li y31 、( - O3S-C≡CCH(CH3)CH2-SO3 - )H x32 Li y32 .

[0128] In the embodiment, when the carboxylic anhydride contained in the above compound is replaced by -PO3 2- When replacing, containing -PO3 2- The compound includes at least one of the following compounds:

[0129] (CH2=CH-PO3 2- )H x33 Na y33 、( -2 O3P-CH=CH-PO3 2- )H x34 Mg y34 、( -2 O3P-CH=CH-PO3 2- )H x35 Na y35 、( -2 O3P-CH=CH-PO3 2- )H x36 Li y36 、(CH(CH3)=CH-PO3 2- )H x37 Na y37 、( -2 O3P-C(C2H5)=CH-PO3 2- )H x38 Li y38 、( --2 O3P-C(CH3)=CHCH2-PO3 2- )H x39 Li y39 、( -2 O3P-CH2C(PO3 2- )=CH2)H x40 Li y40 、( -2 O3P-C(PO3 2- )=CHCH3)H x41 Li y41 、( -2 O3P-CH2CH2CH2-C(PO3 2-)=CHCH3)H x42 Li y42 、( -2 O3P-C(CH(CH3)CH2-PO3 2- )=CHCH3)H x43 Li y43 、( -2 O3P-C(C2H5)=C(CH2CH2CH3)CH2CH2-PO3 2- )H x44 Li y44 、(HC≡C-PO3 2- )H x45 Li y45 、( -2 O3P-C≡C-PO3 2- )H x46 Li y46 、( -2 O3PCH2C≡C-PO3 2- )H x47 Li y47 、( -2 O3P-C≡CCH(CH3)CH2-PO3 2- )H x48 Li y48 .

[0130] In the embodiment, when the carboxylic anhydride contained in the above compound is replaced by -BO2H - When substituted, containing -BO2H - The compound includes at least one of the following compounds:

[0131] (CH2=CH-BO2H - )H x49 Na y49 、( - HO2B-CH=CH-BO2H - )H x50 Mg y50 、( - HO2B-CH=CH-BO2H - )H x51 Na y51 、( - HO2B-CH=CH-BO2H - )H x52 Li y52 、(CH(CH3)=CH-BO2H - )H x53 Na y53 、( - HO2B-C(C2H5)=CH-BO2H - )Hx54 Li y54 、( - HO2B-C(CH3)=CHCH2-BO2H - )H x55 Li y55 、( - HO2B-CH2C(BO2H - )=CH2)H x56 Li y56 、( - HO2B-C(BO2H - )=CHCH3)H x57 Li y57 、( - HO2B-CH2CH2CH2-C(BO2H - )=CHCH3)H x58 Li y58 、( - HO2B-C(CH(CH3)CH2-BO2H - )=CHCH3)H x59 Li y59 、( - HO2B-C(C2H5)=C(CH2CH2CH3)CH2CH2-BO2H - )H x60 Li y60 、(HC≡C-BO2H - )H x61 Li y61 、( - HO2B-C≡C-BO2H - )H x62 Li y62 、( - HO2B-CH2C≡C-BO2H - )H x63 Li y63 、( - HO2B-C≡CCH(CH3)CH2-BO2H - )H x64 Li y64 .

[0132] In addition, x such as x1 to x64 and y such as y1 to y64 in the above unsaturated organic compounds all satisfy the above relationship: x+k×y=a, a=1~8, which can be selected as 1~4, 1~2, and 0≤x / a≤0.2, 0.8≤k×y / a≤1. x M y When the acid group in the nitrogen of the unsaturated organic compound is a phosphate group, a may be equal to 8.

[0133] As in the example, when NH x M y (CH2=CH-COO - )H x1 Na y1 When a=1, k=1, x1+k×y1=a, 0≤x1 / a≤0.2, 0.8≤k×y1 / a≤1, specifically according to a=1, k=1, then x1+y1=1, 0≤x1≤0.2, 0.8≤y1≤1.

[0134] When NH x M y for( - OOC-CH=CH-COO - )H x2 Mg y2 When x2+k×y2=a, and a=2, k=2, 0≤x2 / a≤0.2, 0.8≤k×y2 / a≤1. Specifically according to a=2, k=2, then x2+2y2=2, 0≤x2 / 2≤0.2, 0.8≤2y2 / 2=y2≤1.

[0135] When NH x M y for( - OOC-CH=CH-COO - )H x3 Na y3 When at least one of the following is true, x3+k×y3=a, and a=2, k=1, 0≤x3 / a≤0.2, 0.8≤k×y3 / a≤1. Specifically, according to a=2, k=1, then x3+y3=2, 0≤x3 / 2≤0.2, 0.8≤y3 / 2≤1.

[0136] When NH x M y (CH2=CH-PO3 2- )H x33 Na y33 When at least one of the following is true, x33+k×y33=a, and a=2, k=1, 0≤x33 / a≤0.2, 0.8≤k×y33 / a≤1. Specifically, according to a=2, k=1, then x33+y33=2, 0≤x33 / 2≤0.2, 0.8≤y33 / 2≤1.

[0137] By selecting and controlling the acid radical groups and alkaline metal ion contents in the unsaturated organic matter, if the above NH x M yWhen the relationship between x and y is in the middle range, the promoting effect of acid groups and alkaline metal ions on the formation of artificial SEI film can be relatively significantly enhanced, the content, stability and growth rate of the artificial SEI film can be further improved, and the consumption of lithium, sodium and other ions contained in the battery can be reduced, thereby further improving the first coulombic efficiency and cycle performance of the battery.

[0138] In addition, based on the unsaturated organic matter in the above embodiments, the unsaturated organic matter can be a small molecule organic matter such as a monomer. In the embodiment, the number average molecular weight of the small molecule organic matter can be 70-700, and further can be 70-200.

[0139] Based on the unsaturated organic matter in each of the above embodiments, in an exemplary embodiment, the unsaturated organic matter may specifically include at least one of the unsaturated organic matter shown in the molecular structure formula in Table 1 below:

[0140] ( - OOC-CH=CH-COO - )H 0.1 Na 1.9 、( - OOC-CH=CH-COO - )H 0.4 Na 1.6 、( - OOC-CH=CH-COO - )H 0.1 Li 1.9 、( - OOC-CH=CH-COO - )H 0.1 K 1.9 、( - OOC-CH=CH-COO - )H 0.1 Cs 1.9 、( - OOC-CH=CH-COO - )H 0.1 Ca 0.95 、( - OOC-CH=CH-COO - )H 0.1 Mg 0.95 、(-OOC-CH=CH-COO-)H 0.1 Al 0.63 、(CH(CH3)=CH-COO - )H 0.05 Na 0.95 、( - OOC-C(C2H5)=CH-COO - )H 0.1 Li1.9 、( - OOC-CH2C(COO - )=CH2)H 0.1 Li 1.9 、( - OOC-C(COO - )=CHCH3)H 0.1 Li 1.9 、(HC≡C-COO - )H 0.05 Li 0.95 、( - OOC-C≡C-COO - )HLi、(CH2=CH-COO - )H 0.05 Li 0.95 、(CH2=CH-SO3 - )H 0.0 5Li 0.95 、(CH2=CH-PO3 2- )HLi、(CH2=CH-BO2H - )H 0.05 Li 0.95 .

[0141] These unsaturated organic compounds all have the above-mentioned ability to effectively participate in and form an artificial SEI film, and increase the content and stability of the artificial SEI film, thereby effectively improving the first coulombic efficiency and cycle performance of the battery.

[0142] Electrode preparation method

[0143] In a second aspect, embodiments of the present application further provide a method for preparing the above-mentioned electrode. In some embodiments, the method for preparing the electrode provided in embodiments of the present application comprises the following steps:

[0144] S10: mixing the SEI film-forming additive with the active material to prepare an electrode slurry;

[0145] S20: forming a film of the electrode slurry on the current collector to prepare an active layer.

[0146] The SEI film-forming additive in step S10 is the SEI film-forming additive contained in the active layer 12 of the electrode 10 in the embodiment of the above application. The SEI film-forming additive includes unsaturated organic matter.

[0147] In this way, the electrode preparation method of the embodiment of the present application directly prepares the SEI film-forming additive and the active layer component into an electrode slurry, so that the SEI film-forming additive can be dispersed in the prepared active layer. After the prepared electrode is assembled into a battery, an artificial SEI film can be formed on the electrode during the first charge and discharge process of the battery or before the first charge and discharge, and the artificial SEI film has good stability, thereby significantly improving the first coulombic efficiency and cycle performance of the battery. Moreover, the SEI film-forming additive containing unsaturated organic matter is directly prepared into an electrode slurry with the active material to prepare the electrode, thereby achieving high electrode preparation efficiency and quality stability.

[0148] Step S10:

[0149] The unsaturated organic matter contained in the SEI film-forming additive in step S10 can specifically be the unsaturated organic matter contained in the active layer 12 of the electrode 10 in the embodiment of the above-mentioned application. Similarly, the electrode slurry prepared in step S10 is the electrode slurry that forms the active layer 12 in the electrode 10 in the embodiment of the above-mentioned application, and therefore must contain the components contained in the active layer 12 in the electrode 10 in the embodiment of the above-mentioned application, such as active materials or further components such as binders and conductive agents. Of course, the electrode slurry also contains a solvent, which can be an organic solvent suitable for preparing electrode slurries or water.

[0150] In the embodiment, in the electrode slurry prepared in step S10, the SEI film-forming additive is mixed with the active material to ensure that in the active layer prepared in step S20, the unsaturated organic matter contained in the SEI film-forming additive accounts for 0.2% to 3% of the total mass of the active layer, and can be optionally 0.5% to 1.5%.

[0151] In an embodiment, the pH of the electrode slurry prepared in step S10 can be controlled to be between 6 and 10.5, optionally between 6.8 and 9. In exemplary embodiments, the pH can be 6, 6.8, 7, 7.5, 8, 8.5, 9, 10, or 10.5. Adjusting the pH of the prepared electrode slurry can improve the uniformity of the dispersion of the various components in the electrode slurry and the stability of the slurry. This can effectively reduce the occurrence of floating in the electrode slurry, reduce the consumption of ions such as lithium ions in the electrode slurry, and reduce side reactions in the electrode slurry. This can improve the processability and film-forming properties of the electrode slurry, thereby improving the quality of the active layer in step S20. It can also ensure that the SEI film-forming additives, especially the unsaturated organic matter contained therein, can fully contact the electrode active material, ideally forming a film layer that covers the surface of the electrode active material. Therefore, by adjusting the pH of the electrode slurry, the capacity of the prepared electrode and the quality of the artificial SEI film grown in the battery can be improved, such as the artificial SEI film being able to contact the electrode active material or further cover the surface of the electrode active material. The quality of the artificial SEI film includes properties such as the uniformity, content and stability of the film layer.

[0152] In addition, the mixing process in step S10 can be performed according to conventional electrode slurry preparation methods, such as, but not limited to, stirring, until the components are evenly dispersed to form a stable electrode slurry. Of course, the viscosity and other properties of the electrode slurry should meet the requirements of the film forming process so that an active layer that meets the quality requirements can be formed on the current collector.

[0153] Step S20:

[0154] Based on the components of the electrode slurry in step S10, the active layer prepared in step S20 is the active layer 12 contained in the electrode 10 of the embodiment of the above application. Similarly, the current collector in step S20 is also the current collector 11 contained in the electrode 10 of the embodiment of the above application.

[0155] In step S20, the electrode slurry is formed into a film on the current collector using conventional methods for forming an active layer. For example, in the embodiment, the electrode slurry may be first formed into a wet film on the current collector; then, a drying process is performed to evaporate the solvent, thereby drying the wet film; and then, the dried film layer is rolled to form an active layer, thereby obtaining an electrode.

[0156] Of course, the active layer can also be prepared by improving the conventional active layer preparation method, or by adopting a new method. As long as the electrode slurry in step S10 is used to prepare the active layer on the current collector, it is within the scope disclosed in the embodiment of this application.

[0157] Battery

[0158] In a third aspect, the present invention also provides a battery. The battery comprises an electrode, which is the electrode described in the above embodiment of the present invention.

[0159] Since the battery of the embodiment of the present application contains the electrode of the embodiment of the present application, the battery of the embodiment of the present application has high first coulombic efficiency and good cycle performance.

[0160] In the embodiment, when the negative electrode of the battery of the embodiment of the present application is the electrode of the embodiment of the above text application, the electrode of the embodiment of the above text application is the negative electrode, then the current collector contained therein is the negative electrode current collector, and the active layer is the negative electrode active layer. In this way, the battery of the embodiment of the present application can form an artificial SEI film on the negative electrode during the first charge and discharge process or before the first charge and discharge. At this time, a polymer formed by the polymerization of unsaturated organic matter contained in its negative electrode active layer is provided on the negative electrode on which the artificial SEI film is generated, and the polymer constitutes one of the main components of the artificial SEI film. Therefore, the artificial SEI film has good stability and can further reduce the active ions in the battery, such as lithium or sodium ions, thereby significantly improving the first coulomb efficiency and cycle performance of the battery. After testing, the first coulomb efficiency (first efficiency) of the battery of the embodiment of the present application can be above 80%; and the cycle retention rate can be above 93%.

[0161] Of course, the battery of the present invention may include other necessary components or auxiliary components in addition to the above-mentioned electrodes. For example, when the battery of the present invention is an ion battery, the battery of the present invention may include components or parts such as a separator and an electrolyte.

[0162] When the battery of the present invention contains an electrolyte, in the embodiments, the electrolyte contained in the battery of the present invention also contains an initiator. The initiator is capable of initiating a polymerization reaction of the SEI film-forming additive in the active layer of the electrode of the present invention. Adding the initiator to the electrolyte can, under appropriate conditions, induce a polymerization reaction of the SEI film-forming additive in the active layer of the electrode, more specifically, induce a polymerization reaction of unsaturated organic matter to form an artificial SEI film.

[0163] When the electrolyte of the battery of the embodiment of the present application contains the above-mentioned initiator, the content of the initiator can be selected and controlled according to the content of the SEI film-forming additive, specifically the unsaturated organic matter, in the active layer of the electrode of the embodiment of the present application contained in the ion battery, so that the SEI film-forming additive, specifically the unsaturated organic matter, can fully undergo polymerization reaction, effectively generate an artificial SEI film, and improve the uniformity and stability of the distribution of the artificial SEI film.

[0164] In an embodiment, the mass content of the initiator in the electrolyte of the battery of the embodiment of the present application can be controlled to be 0.01% to 1.0%, optionally 0.2% to 0.6%. In exemplary embodiments, it can be 0.01% to 0.05%, 0.05% to 0.1%, 0.1% to 0.2%, 0.2% to 0.3%, 0.3% to 0.4%, 0.4% to 0.5%, 0.5% to 0.6%, 0.6% to 0.7%, 0.7% to 0.8%, 0.8% to 0.9%, 0.9% to 1.0%, etc. Typical but non-limiting content ranges. The content of the initiator in this range matches the content of the SEI film-forming additive in the active layer of the electrode, such as the negative electrode, so that the SEI film-forming additive, specifically the unsaturated organic matter, can fully undergo polymerization reaction, effectively generate an artificial SEI film, and improve the uniformity and stability of the distribution of the artificial SEI film. At the same time, it can also increase the relatively high content of components such as electrolytes in the electrode solution.

[0165] In an exemplary embodiment, the initiator may include at least one of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, and benzoyl peroxide. These initiators can effectively enable the SEI film-forming additive, specifically unsaturated organic matter, in the active layer of an electrode, such as a negative electrode, to undergo sufficient polymerization reaction, effectively forming a stable artificial SEI film.

[0166] In the embodiments, the batteries of the above embodiments may include any one of a battery cell, a battery module, and a battery pack.

[0167] A battery cell is a battery cell comprising a battery housing and an electrode assembly encapsulated within the battery housing. The shape of a battery cell is not particularly limited and may be cylindrical, square, or any other shape. In one example, the battery cell may be a square-shaped battery cell 20 as shown in FIG3 .

[0168] In some embodiments, as shown in FIG4 , the outer packaging of the battery cell 20 may include a shell 21 and a cover plate 23. The shell 21 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. The shell 21 has an opening connected to the receiving cavity, and the cover plate 23 is used to cover the opening to close the receiving cavity. The positive electrode, diaphragm and negative electrode contained in the battery cell 20 of the embodiment of the present application can be formed into an electrode assembly 22 through a winding process and / or a lamination process. The electrode assembly 22 is encapsulated in the receiving cavity. The electrolyte is impregnated in the electrode assembly 22. The number of electrode assemblies 22 contained in the battery cell 20 can be one or more, which can be adjusted according to actual needs. Among them, the negative electrode in the electrode assembly 22 can be the electrode of the embodiment of the above-mentioned application. Of course, it is not ruled out that the positive electrode in the electrode assembly 22 can be the electrode of the embodiment of the above-mentioned application.

[0169] The preparation method of the battery cell 20 is well known. In some embodiments, the positive electrode, the separator, the negative electrode and the electrolyte can be assembled to form the battery cell 20. As an example, the positive electrode, the separator and the negative electrode can be formed into an electrode assembly 22 through a winding process or a lamination process. The electrode assembly 22 is placed in an outer package, dried and injected with electrolyte, and then subjected to vacuum packaging, standing, forming, shaping and other processes to obtain the battery cell 20. Since the battery cell 20 contains the electrode of the embodiment of the above-mentioned application. Therefore, during the formation process and / or the charging and discharging process, especially the first charging and discharging process, the SEI film-forming additive in the active layer of the electrode of the embodiment of the above-mentioned application, specifically the unsaturated organic matter, will undergo a chemical reaction to form an artificial SEI film on the electrode, and the artificial SEI film has good stability, thereby effectively reducing the consumption of components including active ions and organic solvents in the battery cell 20, reducing the irreversible capacity in the battery cell 20, and further improving the first coulombic efficiency and cycle performance of the battery cell.

[0170] In an embodiment, when the battery of the present application is an ion battery and the electrolyte contains the initiator described above, after the electrolyte injection process of the battery cell 20 and before the formation process, the battery cell 20 may also be subjected to a heat soaking process, that is, a heat soaking process in the electrolyte. The heat soaking process of the battery cell 20 before the formation process accelerates the electrolyte soaking of the battery cell 20, which can effectively shorten the time the battery cell 20 spends in the static and formation processes. More importantly, during the heat soaking process, the initiator can be promoted and accelerated to play the role described above, effectively allowing the SEI film-forming additive, specifically the unsaturated organic matter, in the active layer of the electrode, such as the negative electrode, in the battery cell 20 to fully undergo polymerization reaction, effectively forming a stable artificial SEI film, thereby further reducing the consumption of components such as active ions and organic solvents in the battery cell 20, further reducing the irreversible capacity in the battery cell 20, and further improving the initial coulombic efficiency and cycle performance of the battery cell.

[0171] In an embodiment, when the packaging process of the battery of the present application, specifically the battery cell 20, includes a heat soak treatment, the temperature of the heat soak treatment may be 60-80°C. By adjusting the temperature of the heat soak treatment within this range, the initiator can promote the polymerization reaction of the unsaturated organic SEI film-forming additive contained in the active layer of the electrode, thereby improving the efficiency and stability of the formation of the artificial SEI film. Within this temperature range, the heat soak treatment time should be sufficient to allow the unsaturated organic SEI film-forming additive components to react and form an artificial SEI film.

[0172] In the embodiment, when the battery of the embodiment of the present application is a battery module, the battery module refers to being assembled from the battery cells 20, that is, it can contain multiple battery cells 20, and the specific number can be adjusted according to the application and capacity of the battery module.

[0173] In some embodiments, FIG5 is a schematic diagram of an exemplary battery module 30. As shown in FIG5 , in the battery module 30, multiple battery cells 20 may be arranged sequentially along the length of the battery module 30. Of course, any other arrangement is also possible. Furthermore, the multiple battery cells 20 may be secured using fasteners.

[0174] Optionally, the battery module 30 may further include a housing having an accommodation space, and the plurality of battery cells 20 may be accommodated in the accommodation space.

[0175] A battery pack is assembled from the battery cells 20 described above, and may contain multiple battery cells 20, wherein multiple battery cells 20 may be assembled into the battery module 30 described above. The specific number of battery cells 20 or battery modules 30 contained in a battery pack may be adjusted according to the application and capacity of the battery pack.

[0176] In the embodiment, Figures 6 and 7 are schematic diagrams of an exemplary battery pack 40. The battery pack 40 may include a battery box and multiple battery modules 30 disposed within the battery box. The battery box includes an upper box body 41 and a lower box body 42. The upper box body 41 covers the lower box body 42 and forms an enclosed space for accommodating the battery modules 30. The multiple battery modules 30 may be arranged in any manner within the battery box.

[0177] Electrical devices

[0178] On the fourth aspect, the embodiments of the present application also provide an electric device. The electric device of the embodiments of the present application includes a power supply unit or an energy storage unit, and of course may also include other auxiliary components or necessary components. Among them, the power supply unit or energy storage unit contains the battery of the above-mentioned embodiment of the application. The battery contained in the power supply unit or energy storage unit may be one or more. When there are multiple batteries, multiple batteries can form a battery module or battery pack. Since the electric device of the embodiments of the present application contains the battery of the above-mentioned embodiment of the application, the power supply unit or energy storage unit of the electric device of the embodiments of the present application has high energy density, good cycle performance, and long service life, and the standby or battery life of the electric device of the embodiments of the present application is long.

[0179] Figure 8 is a schematic diagram of an exemplary electric device. This device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the high power and high energy density requirements of this device, a battery pack or battery module may be used.

[0180] As another example, the electric device may be a mobile phone, a tablet computer, a laptop computer, etc. Such an electric device is usually required to be lightweight and thin, and may use a secondary battery as a power source.

[0181] Energy storage device

[0182] In a fifth aspect, an embodiment of the present application further provides an energy storage device, which includes an energy storage unit and, of course, may also include other auxiliary components or necessary components. Among them, the energy storage unit contains the battery of the above-mentioned embodiment of the application. The battery contained in the energy storage unit may be one or more. When there are multiple batteries, multiple batteries can form a battery module or battery pack. Since the energy storage device of the embodiment of the present application contains the battery of the above-mentioned embodiment of the application, the energy storage device has good cycle performance, long service life, and further high energy density.

[0183] Example

[0184] Below, the embodiment of the present application is described. The embodiment described below is exemplary and is only used to explain the present application, and is not to be construed as limiting the present application. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used that do not specify the manufacturer are conventional products that can be obtained commercially.

[0185] 1. Electrode and Preparation Method Example

[0186] Example A1

[0187] This embodiment provides a negative electrode sheet and a method for preparing the same. The negative electrode sheet of this embodiment includes a copper foil and a negative electrode active layer bonded to two opposing surfaces of the copper foil. The copper foil is 6 μm thick; the negative electrode active layer is 146 μm thick, and the negative electrode active layer is doped with an unsaturated organic SEI film-forming additive consisting of maleic acid and sodium, as shown in the following Table 1 by content and structural formula. The molecular formula of maleic acid and sodium is as follows:

[0188] ( - OOC-CH=CH-COO - )H x Na y , where x+k×y=a, and a=2, k=1, x / a=0.05, k×y / a=0.95.

[0189] The method for preparing the negative electrode sheet of this embodiment includes the following steps:

[0190] S1: The negative electrode active material (graphite), thickener (CMC), conductive agent (SP), binder (SBR), and SEI film-forming additive X are uniformly mixed in a certain mass ratio; deionized water is then added as a solvent, and the mixture is stirred in a vacuum mixer until the system becomes uniform to obtain a negative electrode active slurry; wherein the pH of the negative electrode active slurry is 7.54; the mass ratio of graphite, CMC, SP, and SBR in the negative electrode active slurry is 96.2:1.1:0.7:2.0; the amount of SEI film-forming additive X added is according to the content in Table 1 below;

[0191] S2: directly coating the negative electrode active slurry on a 6 μm thick copper foil to form a wet film, which is then dried and cold pressed to form a negative electrode active layer to obtain a negative electrode sheet;

[0192] Example A2 to Example A27

[0193] Examples A2 through A27 each provide a negative electrode sheet and a method for preparing the same. The negative electrode sheets provided in Examples A2 through A27 differ from those in Example A1 in that at least one of the content and type of an organic SEI film-forming additive doped in the negative electrode active layer is different. The content and type of the organic SEI film-forming additive doped in the negative electrode active layer in each example are specifically as shown in Table 1 below. All other aspects are the same as those of the negative electrode sheet in Example A1.

[0194] The preparation methods of the negative electrode sheets in Examples A2 to A27 are respectively prepared according to the preparation method of the negative electrode sheet in Example A1, except that the addition amount and type of the organic SEI film-forming additive in Step S1 of Examples A2 to A27 are adjusted according to the content and type of the organic SEI film-forming additive contained in each Example shown in Table 1 below, and the pH of the negative electrode active slurry prepared in Step S1 of Examples A2 to A27 is adjusted according to the pH of the negative electrode active slurry of each Example shown in Table 1 below. Otherwise, the preparation method is the same as in Example A1.

[0195] Example A28 to Example A30

[0196] Embodiments A28 to A30 of the present invention respectively provide a negative electrode sheet and a preparation method thereof.

[0197] The negative electrode sheets provided in Examples A28 to A30 are respectively different from those in Example A1 in terms of the content and type of the organic SEI film-forming additive doped in the negative electrode active layer. The content and type of the organic SEI film-forming additive doped in the negative electrode active layer in each example are specifically shown in Table 1 below. The rest are the same as the negative electrode sheet in Example A1.

[0198] The preparation methods of the negative electrode sheets in Examples A28 to A30 are respectively prepared according to the preparation method of the negative electrode sheet in Example A1, except that the addition amount and type of the organic SEI film-forming additive in Step S1 of Examples A28 to A30 are adjusted according to the content and type of the organic SEI film-forming additive contained in each Example shown in Table 1 below, the pH of the negative electrode active slurry prepared in Step S1 of Examples A28 to A30 is also adjusted according to the pH of the negative electrode active slurry of each Example shown in Table 1 below. Otherwise, the preparation method is the same as in Example A1.

[0199] Comparative Example A1

[0200] This comparative example provides a negative electrode sheet and a preparation method thereof. Compared with Example A1, the negative electrode sheet of this comparative example is the same as the negative electrode sheet in Example A1 except that the active layer does not contain maleic acid + Na in Example A1.

[0201] Table 1

[0202] 2. Battery Cell Example

[0203] Example B1 to Example B35 and Comparative Example B1

[0204] Embodiments B1 to B35 and comparative example B1 each provide an ion battery cell. Each ion battery cell includes an electrode assembly formed by a positive electrode, a separator, and a negative electrode, and also includes an electrolyte.

[0205] The ion battery cells in Examples B1 to B35 and Comparative Example B1 were assembled as follows:

[0206] Positive electrode sheet: The positive electrode active material (lithium iron phosphate), conductive agent (SP), and binder (PVDF) are mixed uniformly in a mass ratio of 6.8:1.0:2.2, and then NMP is added as a solvent. The mixture is stirred in a vacuum mixer until the system becomes uniform to obtain a positive electrode active slurry. The positive electrode active slurry is directly coated on a 13μm aluminum foil and cold pressed to obtain a positive electrode sheet.

[0207] Negative electrode sheet: the negative electrode sheet provided by Examples A1 to A30 and Comparative Example A1;

[0208] Electrolyte: The organic solvent is a mixture containing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC), wherein the volume ratio of EC, EMC, and DEC is 30:30:40. In an argon atmosphere glove box with a water content of <0.1 ppm, fully dried lithium salt LiPF6 is dissolved in the organic solvent and mixed uniformly to obtain an electrolyte. The concentration of the lithium salt is 1 mol / L. In the electrolytes contained in the battery cells of Examples B28 to B31, initiators of the types and amounts shown in Table 2 below are additionally added.

[0209] Isolation film: Use 12μm thick polyethylene isolation film.

[0210] Battery assembly: The above-mentioned positive electrode sheets, isolation membranes and negative electrode sheets are stacked in order, so that the isolation membrane is placed between the positive electrode sheet and the negative electrode sheet to play an isolating role, and then wound to obtain each bare battery cell. Each bare battery cell is placed in an outer package, and then the electrolyte is injected into each cell and packaged to obtain the battery cells of Example B1 to Example B35 and Comparative Example B1. Among them, the positive electrode sheets contained in the battery cells in Example B1 to Example B35 and Comparative Example B1 are the same, and the difference lies in the negative electrode sheet, and the negative electrode sheet and the electrolyte contained in each battery cell are shown in Table 2 below. The battery cells in Example B32 to Example B35 are subjected to high-temperature electrolyte infiltration treatment according to the conditions shown in Table 2 during the static process before the formation treatment.

[0211] Ion battery monomer related performance test:

[0212] First efficiency of battery cell (%): the first discharge capacity of the battery cell divided by the first charge capacity; wherein, the conditions for the first discharge capacity are: maintaining an ambient temperature of 25°C, first subjecting the battery to low-current formation (0.1C charging for 2 hours), recording the formation capacity C1, aging at 45°C for 24 hours, charging at 0.33C to 3.65V, then constant-voltage charging to 0.04C, recording the capacity C2, and then discharging at 0.33C to 2.5V, recording the discharge capacity D0, first efficiency = D0 / (C1+C2).

[0213] Cycle retention rate (%): capacity after 100 cycles / initial capacity * 100%; where the battery cell is cycled 100 times under the following conditions: repeated charge and discharge at a rate of 0.5C in the voltage range of 2.5-3.65V at a temperature of 45°C. 100-cycle cycle retention rate = 100th cycle discharge capacity / first cycle discharge capacity.

[0214] The relevant performance tests of ion battery cells are shown in Table 2 below:

[0215] Table 2

[0216] As can be seen from the data in Table 2, the first efficiency and cycle retention rates of the battery cells in Comparative Examples B1 to B35 are significantly higher than those of the battery cell in Comparative Example B1. Therefore, it is proven that adding an unsaturated organic SEI film-forming additive to the active layer of the electrode can effectively form an artificial SEI film on the battery cell, specifically on the negative electrode sheet, and that the artificial SEI film has good stability. At the same time, it reduces the consumption of active lithium ions in the battery cell and reduces the irreversible capacity in the battery cell, thereby significantly improving the first coulombic efficiency and cycle performance of the battery cell.

[0217] Further comparison of Examples B1 to B8 shows that the content of unsaturated organic SEI film-forming additives in the electrode sheet, specifically in the active layer of the negative electrode sheet, has a certain influence on the first effect and cycle performance of the battery cell. For example, the first effect and cycle performance of the battery cells in Examples B2 to B7 are better than those in Examples B1 and B8. Among them, the first effect and cycle performance of the battery cells in Examples B3 to B6 are better than those in Examples B1, B2, B7, and B8. Therefore, the content of unsaturated organic SEI film-forming additives in the electrode active layer can be controlled at 0.2% to 3%, and further at 0.5% to 1.5%.

[0218] Comparing Example B4 with Example B9 to Example B27, it can be seen that the type of unsaturated organic SEI film-forming additive in the electrode active layer will affect the first efficiency and cycle performance of the battery cell. Among them, organic SEI film-forming additives containing acid groups can further improve the first efficiency and cycle performance of the battery cell relative to organic SEI film-forming additives without acid groups; organic SEI film-forming additives containing acid groups and alkaline metal ions can further improve the first efficiency and cycle performance of the battery cell relative to organic SEI film-forming additives containing only acid groups; organic SEI film-forming additives containing neither acid groups nor alkaline metal ions are relatively weaker in improving the first efficiency and cycle performance of the battery cell relative to organic SEI film-forming additives containing only acid groups or further containing alkaline metal ions.

[0219] By comparing Example B28 with Example B1 and Example B10 separately, comparing Example B29 with Example B16 and Example B20 separately, and comparing Example B30 with Example B21 and Example B24 separately, it can be seen that, on the basis of the same type and content of unsaturated organic SEI film-forming additives in the electrode active layer, compounding two or more unsaturated organic SEI film-forming additives in the electrode active layer will improve the initial efficiency and cycle performance of the battery cell.

[0220] Comparing Example B4 with Examples B32 to B35, it can be seen that, on the basis of the same type and content of the unsaturated organic SEI film-forming additive in the electrode active layer, further adding an initiator to the electrolyte of the battery cell can further improve the initial efficiency and cycle performance of the battery cell. Therefore, it is indirectly demonstrated that based on the addition of the unsaturated organic SEI film-forming additive to the electrode active layer, further adding an initiator and other additives to the electrolyte is beneficial to the quality and stability of the artificial SEI film formed on the battery cell, specifically including the negative electrode sheet.

[0221] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An electrode comprising a current collector and an active layer combined with the current collector, characterized in that: The active layer contains a SEI film-forming additive, and the SEI film-forming additive includes an unsaturated organic matter; The unsaturated organic matter includes at least one of the following molecular formulas (I) to (II): R5-C≡C-R6(Ⅱ); Among them, R1 to R6 are the same or different including -C m H n -A x , wherein H represents a hydrogen atom, A represents at least one of an anhydride-containing group or an acid radical group containing an alkaline metal ion; m=0 to 3, n=0 to 6, x can be 0 or 1, and m, n, and x are not 0 at the same time.

2. The electrode according to claim 1, characterized in that: The mass content of the unsaturated organic matter in the active layer is 0.2% to 3%.

3. The electrode according to claim 1 or 2, characterized in that: The unsaturated organic matter includes at least one of an acid radical group and an acid radical group containing an alkaline metal ion.

4. The electrode according to claim 3, characterized in that: The acid group includes at least one of carboxylate, sulfonate, phosphate and borate; The alkaline metal ions include at least one metal ion of Li, Na, K, Cs, Rb, Ca, Mg, and Al.

5. The electrode according to any one of claims 1, 2 and 4, characterized in that: The unsaturated organic matter is NH x M y ; Wherein, N is an organic group containing an unsaturated bond and an acid radical group, H is an ionizable hydrogen atom on the acid radical group, M is an alkaline metal ion, and x and y satisfy the following relationship: x+k×y=a, and a=1-8, 0≤x / a≤0.2, 0.8≤k×y / a≤1; The a is the total valence state of the unsaturated organic matter after ionization, and the k is the valence state of the alkaline metal ion.

6. The electrode according to claim 5, characterized in that: The said NH x M y includes (CH2=CH-COO - )H x1 Na y1 、( - OOC-CH=CH-COO - )H x2 Mg y2 、( - OOC-CH=CH-COO - )H x3 Na y3 、( - OOC-CH=CH-COO - )H x4 Li y4 、(CH(CH3)=CH-COO - )H x5 Na y5 、( - OOC-C(C2H5)=CH-COO - )H x6 Li y6 、( - OOC-C(CH3)=CHCH2-COO - )H x7 Li y7 、( - OOC-CH2C(COO - )=CH2)H x8 Li y8 、( - OOC-C(COO - )=CHCH3)H x9 Li y9 、( - OOCCH2CH2CH2-C(COO - )=CHCH3)H x10 Li y10 、( - OOC-C(CH(CH3)CH2COO - )=CHCH3)H x11 Li y11 、( - OOC-C(C2H5)=C(CH2CH2CH3)CH2CH2-COO - )H x12 Li y12 、(HC≡C-COO - )H x13 Li y13 、( - <h2 style=";text-align:left;direction:ltr">OOC-C≡C-COO<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x14 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y14 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> OOCCH2C≡C-COO<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x15 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y15 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> OOC-C≡CCH(CH3)CH2-COO<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x16 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y16 <h2 style=";text-align:left;direction:ltr"> (CH2 = CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x17 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y17 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-CH=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x18 <h2 style=";text-align:left;direction:ltr"> Mg<h2 style=";text-align:left;direction:ltr"> y18 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-CH=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x19 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y19 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-CH=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x20 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y20 <h2 style=";text-align:left;direction:ltr"> (CH(CH3) = CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x21 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y21 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(C2H5)=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x22 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y22 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(CH3) = CHCH2-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x23 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y23 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-CH2C(SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CH2)H<h2 style=";text-align:left;direction:ltr"> x24 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y24 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x25 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y25 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3SCCH2CH2CH2-C(SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x26 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y26 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(CH(CH3)CH2SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x27 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y27 <h2 style=";text-align:left;direction:ltr">、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C(C2H5) = C(CH2CH2CH3)CH2CH2-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x28 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y28 <h2 style=";text-align:left;direction:ltr"> (HC≡C-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x29 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y29 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C≡C-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x30 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y30 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3SCH2C≡C-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x31 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y31 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> O3S-C≡CCH(CH3)CH2-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x32 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y32 <h2 style=";text-align:left;direction:ltr"> (CH2 = CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x33 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y33 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH=CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x34 <h2 style=";text-align:left;direction:ltr"> Mg<h2 style=";text-align:left;direction:ltr"> y34 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH=CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x35 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y35 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH=CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x36 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y36 <h2 style=";text-align:left;direction:ltr"> (CH(CH3) = CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x37 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y37 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C(C2H5)=CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x38 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y38 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> --2 <h2 style=";text-align:left;direction:ltr"> O3P-C(CH3) = CHCH2-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x39 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y39 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH2C(PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> )=CH2)H<h2 style=";text-align:left;direction:ltr"> x40 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y40 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C(PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x41 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y41 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-CH2CH2CH2-C(PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x42 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y42 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C(CH(CH3)CH2-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> )=CHCH3)H<h2 style=";text-align:left;direction:ltr"> x43 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y43 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C(C2H5)=C(CH2CH2CH3)CH2CH2-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x44 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y44 <h2 style=";text-align:left;direction:ltr"> (HC≡C-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x45 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y45 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C≡C-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x46 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y46 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3PCH2C≡C-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x47 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y47 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> -2 <h2 style=";text-align:left;direction:ltr"> O3P-C≡CCH(CH3)CH2-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x48 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y48 <h2 style=";text-align:left;direction:ltr"> (CH2+CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x49 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y49 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-CH=CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x50 <h2 style=";text-align:left;direction:ltr"> Mg<h2 style=";text-align:left;direction:ltr"> y50 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-CH=CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x51 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y51 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-CH=CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x52 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y52 <h2 style=";text-align:left;direction:ltr"> (CH(CH3) = CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x53 <h2 style=";text-align:left;direction:ltr"> Na<h2 style=";text-align:left;direction:ltr"> y53 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-C(C2H5)=CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> x54 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> y54 <h2 style=";text-align:left;direction:ltr"> 、(<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> HO2B-C(CH3) = CHCH2-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H) x55 Li y55 、( - HO2B-CH2C(BO2H - )=CH2)H x56 Li y56 、( - HO2B-C(BO2H - )=CHCH3)H x57 Li y57 、( - HO2B-CH2CH2CH2-C(BO2H - )=CHCH3)H x58 Li y58 、( - HO2B-C(CH(CH3)CH2-BO2H - )=CHCH3)H x59 Li y59 、( - HO2B-C(C2H5)=C(CH2CH2CH3)CH2CH2-BO2H - )H x60 Li y60 、(HC≡C-BO2H - )H x61 Li y61 、( - HO2B-C≡C-BO2H - )H x62 Li y62 、( - HO2B-CH2C≡C-BO2H - )H x63 Li y63 、( - HO2B-C≡CCH(CH3)CH2-BO2H - )H x64 Li y64 at least one of; Among them, x1 to x64 and y1 to y64 all satisfy: x+k×y=a, a=1~8, 0≤x / a≤0.2, 0.8≤k×y / a≤1.

7. The electrode according to any one of claims 1, 2, 4 and 6, characterized in that: The unsaturated organic matter includes at least one of the unsaturated organic matter shown in the following molecular structure formula: ( - OOC-CH=CH-COO - )H 0.1 Na 1.9 、( - OOC-CH=CH-COO - )H 0.4 Na 1.6 、( - OOC-CH=CH-COO - )H 0.1 Li 1.9 、( - OOC-CH=CH-COO - )H 0.1 K 1.9 、( - OOC-CH=CH-COO - )H 0.1 Cs 1.9 、( - OOC-CH=CH-COO - )H 0.1 Ca 0.95 、( - OOC-CH=CH-COO - )H 0.1 Mg 0.95 、(-OOC-CH=CH-COO-)H 0.1 Al 0.63 、(CH(CH3)=CH-COO - )H 0.05 Na 0.95 、( - OOC-C(C2H5)=CH-COO - )H 0.1 Li 1.9 、( - OOC-CH2C(COO - )=CH2)H 0.1 Li 1.9 、( - OOC-C(COO - )=CHCH3)H 0.1 Li 1.9 、(HC≡C-COO - )H 0.05 Li 0.95 、( - OOC-C≡C-COO - )HLi、(CH2=CH-COO - )H 0.05 Li 0.95 、(CH2=CH-SO3<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> 0.0 <h2 style=";text-align:left;direction:ltr"> 5Li<h2 style=";text-align:left;direction:ltr"> 0.95 <h2 style=";text-align:left;direction:ltr"> (CH2 = CH-PO3<h2 style=";text-align:left;direction:ltr"> 2- <h2 style=";text-align:left;direction:ltr"> )HLi、(CH2=CH-BO2H<h2 style=";text-align:left;direction:ltr"> - <h2 style=";text-align:left;direction:ltr"> H)<h2 style=";text-align:left;direction:ltr"> 0.05 <h2 style=";text-align:left;direction:ltr"> Li<h2 style=";text-align:left;direction:ltr"> 0.95 <h2 style=";text-align:left;direction:ltr"> 。 8. The electrode according to any one of claims 1, 2, 4 and 6, characterized in that: At least a portion of the unsaturated organic matter is combined with the electrode active material contained in the active layer.

9. The electrode according to claim 8, characterized in that: At least part of the SEI film-forming additive forms a coating layer coated on the surface of the electrode active material.

10. The electrode according to any one of claims 1, 2, 4 and 6, characterized in that: The electrode is a negative electrode.

11. A method for preparing an electrode, characterized in that: The steps include: The SEI film-forming additive is mixed with the active material to prepare an electrode slurry; Forming a film of the electrode slurry on a current collector to prepare an active layer; Wherein, the SEI film-forming additive includes unsaturated organic matter; The unsaturated organic matter includes at least one of the following molecular formulas (I) to (II): R5-C≡C-R6(Ⅱ); Among them, R1 to R6 are the same or different including -C m H n -A x , wherein H represents a hydrogen atom, A represents at least one of an anhydride-containing group or an acid radical group containing an alkaline metal ion; m=0 to 3, n=0 to 6, x can be 0 or 1, and m, n, and x are not 0 at the same time.

12. The preparation method according to claim 11, characterized in that: The pH of the electrode slurry is 6 to 10.

5.

13. A battery, characterized in that: The invention comprises the electrode according to any one of claims 1 to 10 or the electrode prepared by the preparation method according to any one of claims 11 to 12.

14. The battery according to claim 13, characterized in that: The electrode is a negative electrode, and a polymer formed by polymerizing the unsaturated organic matter is arranged on the negative electrode.

15. The battery according to claim 13 or 14, characterized in that: The electrolyte contained in the battery contains an initiator, and the initiator is used for the polymerization reaction of the SEI film-forming additive.

16. The battery according to claim 15, characterized in that: The mass content of the initiator in the electrolyte is 0.01% to 1.0%.

17. The battery according to claim 15, characterized in that: The initiator includes at least one of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate and benzoyl peroxide.

18. The battery according to claim 15, characterized in that: The battery is subjected to a heating and soaking treatment before the formation treatment.

19. The battery according to claim 18, characterized in that: The temperature of the heating and soaking treatment is 60-80°C.

20. The battery according to any one of claims 13, 14, 16 to 19, characterized in that: The first coulombic efficiency of the battery is above 80%; and / or The cycle retention rate of the battery is above 93%.

21. An electrical device, characterized in that: A battery comprising any one of claims 13 to 20.

22. An energy storage device, characterized in that: A battery comprising any one of claims 13 to 20.

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