Ningde Amperex Technology Limited

An electrochemical apparatus includes a separator, a positive electrode plate, and an electrolyte solution, where the separator includes a porous layer, and an average pore diameter of the porous layer is 0.5 μm to 18 μm; the electrolyte solution includes propyl propionate, and based on a mass of the electrolyte solution, a mass content of propyl propionate is 25% to 55%; and the positive electrode plate includes a positive active material layer, the positive active material layer includes a conductive agent, the conductive agent includes at least one of conductive carbon black or Ketjen black, and a specific surface area of the conductive agent is 600 m 2 /g to 1100 m 2 /g.

A cell including an electrode assembly, and the electrode assembly being formed by winding a positive electrode plate, a separator, and a negative electrode plate stacked. A negative active material of the negative electrode plate includes a silicon-based material, and two surfaces of the negative current collector are completely coated with the negative active material. At a first straight section, a first corner section, and a second straight section of an innermost turn of the positive electrode plate, two surfaces of the positive current collector are coated with a positive active material. An innermost turn of the negative electrode plate includes a third straight section, a second corner section, and a fourth straight section. The first straight section is located between the third straight section and the fourth straight section, and the third straight section is located between the first straight section and the second straight section.

An electrode assembly includes a negative electrode sheet with a negative electrode current collector and a negative electrode active material layer. A positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. Along a first direction, the number of layers of the positive electrode active material layer in the electrode assembly is N. The electrode assembly includes a first end and a second end opposite to each other along a second direction perpendicular to the first direction. At the first end, an edge of the positive electrode active material layer is a first edge, and an edge of the negative electrode active material layer is a second edge. A distance in the second direction between the first edge of each layer of the positive electrode active material layer and the second edge closest to the first edge along the first direction is D.

An electrochemical apparatus, including a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes a positive electrode current collector and a positive electrode active layer disposed on at least one surface of the positive electrode current collector. The positive electrode active layer includes a central region and an edge region surrounding an outer periphery of the central region, the edge region includes a first positive electrode active material, and the central region includes a second positive electrode active material. A solid-phase diffusion coefficient of the first positive electrode active material is 10 −15 cm 2 /s to 10 −5 cm 2 /s, and a ratio of the solid-phase diffusion coefficient of the first positive electrode active material to a solid-phase diffusion coefficient of the second positive electrode active material is 1:3 to 1:1.05.

A negative electrode active material is granular, and the negative electrode active material includes first particles and second particles, where a sphericity of the first particles is greater than a sphericity of the second particles, the sphericity of the first particles is 0.6 to 1.0, and a particle size D v 50 of the first particles is smaller than a particle size D v 50 of the second particles. Applying the negative electrode active material of this application to a secondary battery can increase a compacted density of a battery electrode plate, thereby increasing the energy density of the secondary battery while improving the cycling performance of the secondary battery.

A battery includes an electrode assembly, a first insulation layer, a second insulation layer, and at least one first adhesion portion. The electrode assembly includes a first surface and a second surface provided back away from the first surface; the first insulation layer is provided on the first surface; the second insulation layer is provided on the first surface and spaced apart from the first insulation layer; and the first adhesion portion is provided on the first surface and located in a zone between the first insulation layer and the second insulation layer.

An electrode assembly includes a first electrode plate and a second electrode plate of opposite polarities. A first current collector includes a first conductive layer, a first insulation layer, and a second conductive layer. A first active material layer is provided with a first groove. A first surface is exposed in the first groove. A second surface is covered by a second active material layer. The second active material layer is provided with a second groove. The first surface is covered by the first active material layer. The second surface is exposed in the second groove. A first tab is at least partially accommodated in the first groove, and is bonded to the first single-side blank foil region by a first adhesive layer. A second tab is at least partially accommodated in the second groove, and is bonded to the second single-side blank foil region by a second adhesive layer.

A battery cell includes a battery cell body, at least two tabs, a first connector and at least two insulators. The first connector is configured to fasten a tail end of an electrode assembly to an outer surface of the battery cell body; the at least two tabs include a first tab and a second tab, and the at least two insulators include a first insulator and a second insulator, where first ends of the first insulator and the second insulator are all provided on the battery cell body, a second end of the first insulator covers part of the first tab, and a second end of the second insulator covers part of the second tab; and in a width direction of the battery cell body, the first insulator is provided close to the first connector, where at least part of the first insulator is located outside the first connector.

A separator includes a base film and an organic coating disposed on one surface of the base film. The organic coating contains a first polymer and a second polymer. A melting point T of the first polymer satisfies 60° C.≤T≤100° C., and a swelling degree D of the second polymer during placement in an electrolyte solution at 60° C. for 24 h satisfies D≤30%.

A battery includes an electrode assembly and a packaging bag. The electrode assembly includes an electrode plate and a separator. The separator includes a porous substrate. A first coating layer is disposed on at least one surface of the porous substrate. The first coating layer includes a first polymer and a second polymer that melt at different melting points. The battery satisfies: 0.077≤(3.0−D 2 /D 1 )/T≤0.118, thereby endowing the battery with superior electrochemical performance, a relatively wide hot-oven window, and a relatively high hot-oven test pass rate.