Search

EP-4148851-B1 - ELECTROCHEMICAL DEVICE AND ELECTRONIC DEVICE

EP4148851B1EP 4148851 B1EP4148851 B1EP 4148851B1EP-4148851-B1

Inventors

  • WANG, KEFEI
  • SHI, LIANG

Dates

Publication Date
20260513
Application Date
20200605

Claims (10)

  1. An electrochemical apparatus, comprising: a positive electrode, a negative electrode and an electrolyte; wherein the positive electrode comprises a positive electrode active material layer; and a contact angle of the positive electrode active material layer with respect to a non-aqueous solvent, as measured by a contact angle measurement method, is not greater than 45°, wherein the contact angle measurement method refers to, after 3 microliters of diethyl carbonate droplets are dropped on a surface of the positive electrode active material layer, measuring a contact angle of the droplets with the surface of the positive electrode active material layer within 100 seconds, characterized in that the electrolyte further contains a compound of formula 1: wherein R is a substituted or unsubstituted C 1 -C 10 alkyl group, and in the case of substitution, a substituent group is halogen, and based on a total weight of the electrolyte, a proportion of the compound of formula 1 is 0.001 wt% to 2 wt%.
  2. The electrochemical apparatus according to claim 1, wherein the positive electrode active material layer comprises an additive having a hydrophilic group and a lipophilic group.
  3. The electrochemical apparatus according to claim 1 or 2, wherein the additive has at least one of the following characteristics: (a) an oxidation potential of not less than 4.5 V and a reduction potential of not greater than 0.5 V; (b) a surface tension of not greater than 40 mN/m; (c) comprising an unsaturated carboxylic acid group; and (d) a proportion of not greater than 3000 ppm based on a total weight of the positive electrode active material layer.
  4. The electrochemical apparatus according to claim 2, wherein the additive comprises at least one of 2-dodecyl acrylate, polyethylene glycol monomethyl ether acrylate, polyethylene glycol dimethacrylate, acrylic acid (2-ethylhexyl) acrylate, acrylate non-ionic fluorocarbon acrylate surfactant, dodecyl methacrylate, acrylic acid (ester) copolymer, copolymer of maleic and acrylic acid, or ethylene acrylic acid copolymer.
  5. The electrochemical apparatus according to claim 1, wherein the compound of formula 1 contains at least one of the following structural formulas: or
  6. The electrochemical apparatus according to claim 1, wherein X mg of the compound of formula 1 in the electrolyte and a reaction area Y m 2 of the positive electrode active material layer satisfy the following relationship: 10≤X/Y≤100.
  7. The electrochemical apparatus according to claim 1, wherein the positive electrode active material layer comprises a positive electrode active material, and the positive electrode active material comprises lithium-containing transition metal oxides having different median particle sizes.
  8. The electrochemical apparatus according to claim 7, wherein the lithium-containing transition metal oxide comprises a compound represented by a general formula (1), Li a M1 b M2 c M3 d O 2 (1), wherein, M1 is at least one selected from Co, Ni, or Mn; M2 is at least one selected from Mg, Ti, Zr, Ge, Nb, Al, or Sn; M3 is an element other than Li, M1, and M2; 0.5 ≤ a < 1.1 ; 0.8 ≤ b < 1.2 ; 0.002 ≤ c ≤ 0.05 ; and 0 ≤ d ≤ 0.05 .
  9. The electrochemical apparatus according to claim 8, wherein the lithium-containing transition metal oxide comprises Mg and at least one metal element selected from the group consisting of Ti, Zr, Ge, Nb, Al, and Sn.
  10. An electronic apparatus, comprising the electrochemical apparatus according to any one of claims 1 to 9.

Description

TECHNICAL FIELD This application relates to the field of energy storage, specifically to an electrochemical apparatus and an electronic apparatus, and in particular to a lithium-ion battery. BACKGROUND With the development of technologies and the increasing demands for mobile apparatuses, demands for electrochemical apparatuses (for example, lithium-ion batteries) have increased significantly, and thus higher requirements are imposed on performance of lithium-ion batteries, especially cycling performance of lithium-ion batteries. Charge/discharge capacity of lithium-ion batteries decreases during cycling, thereby reducing the performance of lithium-ion batteries. The performance of lithium-ion batteries mainly depends on characteristics of the electrodes, electrolyte and separator. Performance of electrodes not only depends on characteristics of the current collector and the active material layer, but is also closely related to additives in the active material layer. The additive is conducive to dispersion of particles or bonding of interfaces in the active material layer. However, during preparation of a lithium-ion battery, problems such as difficulty in proportioning due to poor matching of raw materials are often found, which can adversely affect the performance of the lithium-ion battery. US 2014/178732 A1 teaches a non-aqueous electrolyte secondary battery having a high capacity and an improved cycle life. The battery includes an electrode group and a non-aqueous electrolyte, and has a volume energy density of 650 Wh/L or more. The electrode group includes wound positive and negative electrodes with a separator interposed therebetween. The positive and negative electrodes each include a current collector and a material mixture layer adhering thereto. The positive and negative electrode material mixture layers each have a porosity Pp of 22% or less and porosity Pn of 25% or less. The ratio VE/VT of a volume VE of the electrolyte to a total VT of the pore volumes of the positive and negative electrode material mixture layers, and the separator is 1 to 1.5. The difference between contact angles CAp and CAn of the positive and negative electrodes with respect to the non-aqueous electrolyte is 23° or less. US 2011/045360 A1 relates to a lithium ion secondary battery including: a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, wherein the non-aqueous electrolyte includes a non-aqueous solvent including a fluoroether, the positive electrode includes a positive electrode current collector and a positive electrode active material layer formed on the surface of the positive electrode current collector, the positive electrode active material layer includes lithium-containing composite oxide particles and a fluororesin, and a coverage of the fluororesin relative to the surface area of the lithium-containing composite oxide particles is 20 to 65%. It is an object of the invention to provide a lithium ion secondary battery that is kept from deteriorating in rate characteristics over time, in particular, from significantly deteriorating in rate characteristics during storage at high temperatures. In view of this, it is necessary to provide an electrochemical apparatus and an electronic apparatus that have improved performance. SUMMARY The present invention is defined in the appended claims. Embodiments of this application provide an electrochemical apparatus and an electronic apparatus, so as to resolve at least one problem existing in the related art to at least some extent. The electrochemical apparatus according to the invention is defined by the features of claim 1. The electronic apparatus according to the invention is defined by the features of claim 10. Further embodiments of the invention are defined in the appended claims. DETAILED DESCRIPTION Embodiments of this application are described in detail below. The embodiments of this application should not be construed as limitations on the application. Unless otherwise expressly indicated, the following terms used in this specification have the meanings described below. In the specific embodiments and claims, a list of items connected by the term "at least one of" may mean any combination of the listed items. For example, if items A and B are listed, the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and C" means only A; only B; only C; A and B (exclusive of C); A and C (exclusive of B); B and C (exclusive of A); or all of A, B, and C. The item A may contain a single element or a plurality of elements. The item B may contain a single element or a plurality of elements. The item C may contain a single element or a plurality of elements. The term "at least one type of" has the same meaning as the term "at least one of". An electrode (positive electrode or