Dongguan Amperex Technology Limited

An electrochemical device, including a cathode, an anode and an electrolyte. The anode includes an anode current collector and an anode active material disposed on the anode current collector, the electrolyte includes fluoroethylene carbonate, and the electrochemical device meets the following relationship: 17.55≤K 1 −K 2 −1.63K 3 2 +11.27K 3 ≤20.80, where K 1 represents a specific surface area value of the unit mass of the anode active material (in m 2 /g), and 1.0≤K 1 ≤2.0; K 2 represents a content value of the fluoroethylene carbonate required by per Ah capacity (in g/Ah), and 0.05≤K 2 ≤0.25; and K 3 represents a weight value of the anode active material required by per Ah capacity (in g/Ah).

The present application relates to a secondary battery including a first adapter piece and an electrode assembly, the electrode assembly including a first electrode plate, a second electrode plate, a plurality of electrode tabs and a second electrode tab, all of the first electrode tabs are stacked to form a first multi-tab structure and connected to the first adapter piece, and the electrode assembly comprises a first adapter member; the first adapter member comprises the first multi-tab structure and the first adapter piece; in a direction parallel to the first electrode plate, there is at most one layer of the first adapter member. The present application may effectively reduce the existing waste of the top space caused by bending the electrode tabs, and is more stable for the bending effect, thereby improving the energy density of the battery.

An electrochemical apparatus includes a separator and an electrolyte solution, wherein the separator includes a base film and a first coating disposed on a surface of the base film, the first coating includes a solid-state electrolyte material, and the solid-state electrolyte material includes element Ti; the electrolyte solution includes compound I, and the compound I includes at least one selected from the group consisting of vinylene carbonate, vinyl ethylene carbonate, fluoroethylene carbonate, and 4,5-difluoro-1,3-dioxolan-2-one; and based on a mass of the electrolyte solution, a mass percentage of the compound I is P %, wherein P ranges from 0.5% to 20%, and based on a mass of the first coating, a mass percentage of the element Ti is Q %, wherein 1≤Q/P≤60.

An electrode assembly includes a positive electrode material layer, where the positive electrode material layer of the electrode assembly includes a first positive electrode material LiMn x Fe 1-x PO 4 , a single-side thickness of the positive electrode material layer is T 1 μm, and 22≤T 1 ≤110. A length of a positive electrode plate is L 1 mm. The electrode assembly further includes at least one positive electrode tab. When there is one positive electrode tab, the positive electrode tab is a centrally disposed tab structure; or when there are multiple positive electrode tabs, a ratio of the number of the positive electrode tabs to L 1 is B, and 0.002≤B≤0.01.

This application discloses a packaging bag, a secondary battery, and an electronic device, where the packaging bag includes an encapsulation layer, a metal layer, an adhesive layer, and a packaging layer arranged in a stacked manner. The adhesive layer includes a first thermally conductive material, where a mass percentage of the first thermally conductive material in the adhesive layer is denoted as G 1 , and 1%≤G 1 ≤30%. By incorporating the first thermally conductive material into the adhesive layer, heat generated during operation of the secondary battery can be more effectively conducted away, mitigating temperature rise inside the secondary battery, thereby improving the performance and safety of the secondary battery. Additionally, this enables more uniform heat distribution between the interior of the secondary battery and the packaging bag, reducing localized overheating and extending the service life of the secondary battery.

An electrochemical apparatus includes a positive electrode plate and an electrolyte; where the electrolyte includes an additive A, and the additive A is an organic additive containing lone pair of electrons; and the positive electrode plate includes a positive electrode material layer, the positive electrode material layer includes a positive electrode active material, and the positive electrode active material includes an element M; where the element M includes at least one of Cu or Zn; and based on a mass of the positive electrode active material, a proportion of the element M is t ppm, t satisfying 1≤t≤500.

An electrochemical apparatus includes a positive electrode plate. The positive electrode plate includes a positive electrode material layer. The positive electrode material layer includes a fluorine-containing polymer and a cyano-containing polymer. A ratio b/a of a mole number b of nitrogen to a mole number a of fluorine in the positive electrode material layer satisfies 0.1≤b/a≤0.5. Adding the fluorine-containing polymer and the cyano-containing polymer in the positive electrode material layer and controlling the ratio b/a satisfies the above relationship enable a good bonding effect between particles in the positive electrode material layer. In addition, after cyano functional groups interact with transition metal ions of the positive electrode active material at full charge, oxidizing ability of transition metal ions is weakened, reducing side reactions between the positive electrode material layer and electrolyte, thereby improving high-temperature performance of the electrochemical apparatus.

An electrode assembly includes a first electrode plate, a second electrode plate, and a separator that are wound to form a jelly-roll structure. The electrode assembly includes a first straight portion, a first curved portion, a second straight portion, and a second curved portion. The first straight portion and the second straight portion each include a first part, a second part, and a third part. Along a thickness direction of the first electrode plate, the first electrode plate is locally recessed in at least one of the first curved portion, the second curved portion, the first part, or the third part, so as to form a first recessed portion or portions. The first electrode plate at the first recessed portion is locally recessed to form a second recessed portion or portions. The first recessed portion and the second recessed portion are recessed in the same direction.

A secondary battery is provided, comprising a first adapter piece and an electrode assembly, comprising a first and second electrode plates, a plurality of first electrode tabs, a second electrode tab, a direction parallel to the first electrode plate being L, two end points in a thickness direction being T 1 and T 3 , a position of one of the first electrode tabs farthest from T 1 or T 3 is T 2 ; all the first electrode tabs are stacked to form a first multi-tab structure and connected to the first adapter piece, it further comprises a first adapter member comprising the first multi-tab structure and the first adapter piece; in the L direction, there is at most one layer of the first adapter member. The present application may reduce the existing waste of the top space caused by bending electrode tabs, and is more stable for the bending effect, improving the ED of battery.

An electrode plate includes a current collector and an active material layer provided on the current collector. The active material layer includes a first composite particle including a first active material particle and a first binder particle and a second composite particle including a second active material particle and a second binder particle. In a thickness direction of the active material layer, the first composite particle is closer to the current collector than the second composite particle. A quantity of the first active material particle contained in the first composite particle is greater than a quantity of the second active material particle contained in the second composite particle. Components of both the first binder particle and the second binder particle include polypropylene.