The invention relates to a button lithium ion battery, a preparation method thereof, and a method of producing a lithium ion cell composite flat sheet, wherein the button lithium ion battery comprises a battery housing, a cell accommodated in the battery housing and an electrolyte filled in the battery housing; the cell is formed by winding a composite flat sheet in which a first separator, a positive piece, a second separator and a negative piece are sequentially stacked and hot-laminated to form an integrated structure. The cell of the button lithium ion battery is formed by winding a composite flat sheet, so that winding efficiency can be improved, and misalignment can be avoided; moreover, chances of hand contact can be reduced, the influence of dust and water vapor can be avoided, and the quality of the lithium battery can be improved to the maximum extent.

The invention relates to a button lithium ion battery, a preparation method thereof, and a method of producing a lithium ion cell composite flat sheet, wherein the button lithium ion battery comprises a battery housing, a cell accommodated in the battery housing and an electrolyte filled in the battery housing; the cell is formed by winding a composite flat sheet in which a first separator, a positive piece, a second separator and a negative piece are sequentially stacked and hot-laminated to form an integrated structure. The cell of the button lithium ion battery is formed by winding a composite flat sheet, so that winding efficiency can be improved, and misalignment can be avoided; moreover, chances of hand contact can be reduced, the influence of dust and water vapor can be avoided, and the quality of the lithium battery can be improved to the maximum extent.

A rechargeable button cell having a height-to-diameter ratio less than one, including two metal housing halves separated from one another by an electrically insulating seal or film seal forming a housing having a plane bottom region and a plane top region parallel thereto is disclosed. The housing contains an electrode separator assembly comprising a positive electrode and a negative electrode inside the housing, the electrode separator assembly being provided in the form of a winding, end sides of which face in a direction of the plane bottom region and the plane top region such that layers of the electrode separator assembly are oriented essentially orthogonally to the plane bottom region and plane top region.

A rechargeable button cell having a height-to-diameter ratio less than one, including two metal housing halves separated from one another by an electrically insulating seal or film seal forming a housing having a plane bottom region and a plane top region parallel thereto is disclosed. The housing contains an electrode separator assembly comprising a positive electrode and a negative electrode inside the housing, the electrode separator assembly being provided in the form of a winding, end sides of which face in a direction of the plane bottom region and the plane top region such that layers of the electrode separator assembly are oriented essentially orthogonally to the plane bottom region and plane top region.

The invention relates to a cell coil (30, 40, 50, 60, 100, 200) for a lithium-ion battery, comprising at least two sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82), which are wound in a space-saving manner and are thermally coupled to each other. According to the invention, the at least two sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) are electrically connected in parallel in normal operation, and, in the event of a fault, in particular in the event of an internal short circuit in at least one defective sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82), at least one defective sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) can be electrically separated from the at least one intact sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82). Because of the at least one defective sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) that can be immediately electrically separated from the intact sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) by means of an electronic monitoring device (36) in the “event of a fault”, a high level of robustness of the cell coil (30, 40, 50, 60, 100, 200) in respect of internal short circuits is achieved. Among other things, the intact sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) act, because of the thermal coupling between the sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82), as a damage-reducing heat sink for the waste heat that is released during the fast discharge of the affected defective sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) generally occurring in the event of a short circuit.

The invention relates to a cell coil (30, 40, 50, 60, 100, 200) for a lithium-ion battery, comprising at least two sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82), which are wound in a space-saving manner and are thermally coupled to each other. According to the invention, the at least two sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) are electrically connected in parallel in normal operation, and, in the event of a fault, in particular in the event of an internal short circuit in at least one defective sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82), at least one defective sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) can be electrically separated from the at least one intact sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82). Because of the at least one defective sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) that can be immediately electrically separated from the intact sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) by means of an electronic monitoring device (36) in the “event of a fault”, a high level of robustness of the cell coil (30, 40, 50, 60, 100, 200) in respect of internal short circuits is achieved. Among other things, the intact sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) act, because of the thermal coupling between the sub-cells (10, 32, 42, 44, 52, 54, 68, 70, 80, 82), as a damage-reducing heat sink for the waste heat that is released during the fast discharge of the affected defective sub-cell (10, 32, 42, 44, 52, 54, 68, 70, 80, 82) generally occurring in the event of a short circuit.

A nonaqueous electrolyte secondary battery includes a positive electrode, a nonaqueous electrolytic solution, and a negative electrode. The negative electrode includes a negative electrode current collector and a negative electrode active material layer which is formed on the negative electrode current collector. The negative electrode active material layer has a first region and a second region. The first region is a region formed on a surface of the negative electrode current collector and contains lithium titanium composite oxide as a major component. The second region is a region including a surface of the negative electrode active material layer and contains lithium titanium composite oxide as a major component and further contains silicon oxide.

A nonaqueous electrolyte secondary battery includes a positive electrode, a nonaqueous electrolytic solution, and a negative electrode. The negative electrode includes a negative electrode current collector and a negative electrode active material layer which is formed on the negative electrode current collector. The negative electrode active material layer has a first region and a second region. The first region is a region formed on a surface of the negative electrode current collector and contains lithium titanium composite oxide as a major component. The second region is a region including a surface of the negative electrode active material layer and contains lithium titanium composite oxide as a major component and further contains silicon oxide.

An inspection device (20) for inspecting a structure body (10) including a pair of electrodes and a separator disposed between the pair of electrodes is provided, the inspection device (20) includes: a measurement unit (30) including a direct-current constant voltage generator (32) that generates a constant inspection voltage applied to the pair of electrodes, and a detection circuit (34) that detects a current value between the pair of electrodes resulting from the application of the inspection voltage; and a processing unit (50) that determines whether the structure body (10) is defective or non-defective based on the detected current value, and the processing unit (50) has a function that, if two or more points at which a ratio (ΔI/Δt) of a current value variation amount (ΔI) to a time variation amount (Δt) varies from a value of no less than 0 to a negative value are observed or no point at which the ratio (ΔI/Δt) varies from a value of no less than 0 to a negative value is observed during a period of time immediately after the application of the inspection voltage until the current value becomes constant, determines the structure body (10) as a defective product, and an auxiliary function that obtains a peak current value I.sub.peak, a peak current appearing time t.sub.peak and a current area S.sub.I of a current waveform representing variation in current value I over passage of time t, and if any one of the peak current value I.sub.peak, the peak current appearing time t.sub.peak and the current area S.sub.I deviates from a preset threshold value including an upper limit value and a lower limit value, determines the structure body as a defective product.

A positive electrode plate (11) includes a current collector (30) and a mixture layer (31) disposed on the current collector (30). The mixture layer (31) has a thin portion (32) with a thickness of less than 200 μm disposed on an inner coil half of the current collector (30) and a thick portion (33) having a larger thickness than the thin portion (32), the thick portion (33) having a yield loop height H measured by a stiffness test of 6 mm<H<15 mm.