A nonaqueous electrolyte secondary battery including a positive electrode that includes a lithium-manganese oxide as a positive electrode active material, a negative electrode includes SiO.sub.x (0≤X<2) in which at least a part of a surface is covered with carbon, or a Li-Al alloy as the negative electrode active material, a low-viscosity electrolytic solution that contains propylene carbonate (PC), ethylene carbonate (EC), and dimethoxy ethane (DME) as an organic solvent in a range of {PC:EC:DME}={0.5 to 1.5:0.5 to 1.5:1 to 31} in terms of a volume ratio, and lithium bis(fluorosulfonyl)imide (LiFSI) as a supporting salt in an individual amount of 0.6 to 1.2 (mol/L), and the viscosity of the electrolytic solution is constant at higher than −30° C. to room temperature.

A button-type secondary battery includes an electrode assembly; a lower can configured to accommodate the electrode assembly; an upper can coupled to an opening of the lower can; a gasket configured to electrically insulate the lower can and the upper can from each other; a first tab part configured to connect a first electrode of the electrode assembly to the lower can; and a second tab part configured to connect a second electrode of the electrode assembly to the upper can. The second tab part includes a second electrode tab and a second lead tab. The second electrode tab is connected to the second electrode, and the second lead tab connects the second electrode tab to the upper can.

Embodiments provide a secondary battery and a preparation method thereof, and a battery module, battery pack, and apparatus containing such secondary battery. In those embodiments, a negative electrode plate includes a negative-electrode current collector and a negative-electrode film layer that is disposed on at least one surface of the negative-electrode current collector and that includes a negative-electrode active material. The negative-electrode active material contains graphite, and the negative electrode plate satisfies that, when the negative electrode plate and a lithium metal sheet constitute a button battery which is discharged to 5.0 mV at 0.05 C, a capacity increment curve V-dQ/dV of the button battery has a third-order lithiation phase transition peak of graphite at position 0.055V-0.085V.

A rechargeable lithium-ion button cell battery having a sealed housing includes a top flat plate and a round or oval cup sealed by laser at the rim of top plate whereas connecting the opening end of the cup sidewall. The top plate has a centered sandwiched structure including two outer plates at upper and lower position, that clamping one inner pin-like conductive plate by its flange, insulated by a gasket. The upper plate of the outer plates has an asymmetric shape to its center line, which allows asymmetric sealing force applied on the inner pin-like plate flange to act as a safety vent. Inside the sealed housing the anode and cathode electrodes are either spiral wound or stacked with separator to be a round or oval roll, one electrode is connected to the cup, the other electrode is connected to the inner pin-like conductive plate of the top plate.

A button-type secondary battery includes an electrode assembly; a lower can into which the electrode assembly is disposed; and an upper can configured to cover an opening of an upper end of the lower can. A beading part recessed inward is disposed at an upper portion of the lower can. The upper end of the lower can disposed above the beading part has a bent shape and configured to surround an edge end of the upper can so that the upper can and the lower can are coupled to each other.

A miniature electrochemical cell of a primary or secondary chemistry with a total volume that is less than 0.5 cc is described. The cell has a casing comprising an annular sidewall supported on a lower plate opposite an upper lid. The lid has a sealed electrolyte fill port that is axially aligned with an annulus residing between the inner surface of the annular sidewall and the electrode assembly. The fill port axially aligned with the annulus between the electrode assembly and the casing sidewall allows the casing to be filled with electrolyte using a vacuum filling process so that activating electrolyte readily wets the anode and cathode active materials and the intermediate separator.

A rechargeable battery includes: an electrode assembly including a first electrode, a second electrode, a separator between the first and second electrodes, and first and second electrode tabs respectively coupled to the first and second electrodes; a case accommodating the electrode assembly and coupled to the first electrode tab; and a cap assembly sealing an opening in the case. The cap assembly includes: a cap plate covering the opening in the case; and a terminal plate coupled to the cap plate. The terminal plate includes: a flange portion coupled to and electrically insulated from the cap plate; and a tab connecting portion protruding from the flange portion toward the electrode assembly and extending through a terminal opening in the cap plate to be coupled to the second electrode tab. The terminal plate has a flat outer surface, and the tab connecting portion has a flat inner surface.

A button battery shell includes a positive electrode metal end cover and a negative electrode metal end cover. The positive electrode metal end cover includes a first bottom cover and a first surrounding wall arranged around one side of the first bottom cover. The negative electrode metal end cover includes a second bottom cover and a second surrounding wall provided around one side of the second bottom cover. The positive electrode metal end cover and the negative electrode metal end cover are arranged opposite to each other. First insulating sleeve are arranged on the first surrounding wall. Second insulating sleeves are arranged on the second surrounding wall. The two insulating sleeves are connected at a connection surface to form an insulating shell having an integrated structure. The insulating shell, the positive electrode metal end cover, and the negative electrode metal end cover form an accommodating cavity.

A button cell and a preparation method thereof, where the button cell includes a housing and a roll core; the housing includes a housing body and a top cover assembly, the housing body and the top cover assembly jointly enclose an accommodating cavity for accommodating the roll core; the roll core includes a first tab, and the first tab is welded to a bottom wall of the housing body by laser welding; and a welding area of the first tab has a welding mark, and the welding mark is located in a portion where the bottom wall of the housing body overlaps with the cavity of the roll core, and an outer surface of a welding area of the bottom wall is a smooth surface.

A method for producing a button cell includes providing a metal cell cup, providing a metal cell top, and providing a first electrode and a second electrode. The first electrode includes a first current collector partially coated with a first active electrode material and having an active material-free region. The second electrode includes a second current collector partially coated with a second active electrode material and having an active material-free region. The method further includes attaching a first metal foil conductor to the active material-free region of the first current collector, attaching a second metal foil conductor to the active material-free region of the second current collector, and forming a cylindrical electrode winding by winding, in a spiral, an electrode assembly. The first and second metal foil conductors extend out of the cylindrical electrode winding from first and second end faces of the cylindrical electrode winding.