This application relates to a positive electrode plate and an electrochemical device. The positive electrode plate includes a current collector, a safety coating, a difficultly soluble layer and a positive active material layer, wherein the safety coating, the difficultly soluble layer and the positive active material layer are successively disposed on the current collector; wherein the safety coating includes a polymer matrix, a conductive material and an inorganic filler; wherein the difficultly soluble layer includes a binder and a conductive agent, and wherein the binder of the difficultly soluble layer has a solubility in an oil solvent smaller than the solubility of the polymer matrix of the safety coating in such oil solvent.

A cylindrical secondary battery configured to have a structure to which an adhesion unit, including an adhesive material, a conductive material, and PTC particles, is provided. The adhesion unit is configured to couple a cap assembly, which functions as a positive electrode terminal of the cylindrical secondary battery, and a positive electrode tab of a jelly-roll type electrode assembly to each other.

A battery system includes a plurality of battery cells connected in parallel. Each battery cell includes a positive and negative tab. The battery system also includes a plurality of thermal switch devices (e.g., temperature cut off (TCO) or positive temperature coefficient (PTC) devices). Each thermal switch device is electrically coupled to a respective cell. The battery system further includes a rigid-flex circuit board comprising a plurality of rigid regions. Each rigid region is physically and electrically connected to an adjacent rigid region by a respective flexible region. Each rigid region is electrically coupled to respective positive and negative tabs of a respective battery cell. Each thermal switch device prevents abnormal current flow (e.g., by limiting the flow of current at high temperatures) between a first battery cell that is coupled to the thermal switch device and a second battery cell that is adjacent to the first battery cell.

A temperature-sensitive battery connector is disclosed. The connector can include a connector body and at least one conductor mounted to the connector body and configured to convey a current signal used to measure voltage from a battery pack or battery cell to a battery management system (BMS). The connector can include a thermal switching device mounted to the connector body and thermally coupled to a terminal of a battery pack or a battery cell. The thermal switching device can be configured to provide an overtemperature signal to the BMS by changing or interrupting a current conducted by at least one conductor when a temperature of the battery pack or battery cell exceeds a threshold temperature.

Energy storage devices, battery cells, and batteries of the present technology include a current collector including a polymer film coupled with a plurality of wires of a metal-containing material. The current collector may include a first region and a second region. The first region may be characterized by an extension of the metal-containing material. The polymer film may be contained within the second region of the current collector. Additionally, the plurality of wires may extend from the extension of the metal-containing material along the polymer film.

A battery protection circuit includes: a plurality of pack terminals configured to connect a battery module to an external device; a first fuse element located on a current path between the battery module and the pack terminals to block a current flow between the battery module and the pack terminals depending on a voltage applied to a control terminal thereof; a first integrated circuit configured to include a first input terminal and control a voltage outputted to the control terminal of the first fuse element depending on a voltage applied to the first input terminal; and a plurality of thermistors connected in series between a positive electrode of the battery module and a first input terminal of the first integrated circuit and having resistance that is varied depending on a temperature of a corresponding cell among a plurality of cells constituting the battery module.

A battery (10) for an electric vehicle comprises a plurality of battery cells (11), where a first group (12) comprises a plurality of battery cells (11) connected to each other in parallel, a second group (13) comprises a plurality of battery cells (11) connected to each other in parallel, and the first group (12) and the second group (13) are connected with each other in series forming a first line (14) of battery cells (11). The battery (10) further comprises a first terminal (16) which is configured to be connected with an electric machine (30) and with a power net (31) of the electric vehicle, and a second terminal (17) which is configured to be connected with a reference potential (32). The battery (10) is configured to supply the electric machine (30) and the power net (31) of the electric vehicle with power, and the electric machine (30) and the power net (31) are supplied with the same voltage level by the battery (10).

Provided herein is a positive temperature coefficient film comprising an inorganic positive temperature coefficient compound. Also provided herein are a positive temperature coefficient electrode, a positive temperature coefficient separator, and a positive temperature coefficient lithium secondary battery, each of which comprises the positive temperature coefficient film.

A battery pack includes a cell block including battery cells electrically connected to each other, the cell block having a pair of long sides and a pair of short sides which surround lateral surfaces of the battery cells and are tangent to the lateral surfaces of the battery cells, and a flexible wiring surrounding the cell block in a direction parallel to the pair of long sides of the cell block, the flexible wiring including sensors to detect state information from the battery cells.

An electrode assembly with improved connection between current collectors and electrode tabs, and a method for manufacturing the same, for assuring safety with respect to overcharge, and battery capacity by improving a connection structure between the electrode tab and the current collector are provided. The electrode assembly for a rechargeable battery includes: an electrode current collector; an uncoated region in which an electrode active material layer is not formed, and provided on one side of the electrode current collector; an electrode tab disposed in the uncoated region; and a conductive adhesion portion that is disposed between the uncoated region and the electrode tab. The conductive adhesion portion comprises a positive temperature coefficient (PTC) material.