The present invention provides an electrode for an electrical device, the electrode comprising: a PTC element; a first terminal disposed on one main surface of the PTC element and extending in one direction; and a second terminal disposed on the other main surface of the PTC element and extending in a different direction from the first terminal.

A battery balancing system for parallel connected batteries for balancing batteries that are at dissimilar voltages. The system has first and second buses, connected by a current limiter. A high bus takes energy from the highest voltage battery or batteries in the system and transfers the energy through the current limiter to the low bus, which in turn delivers energy to the lowest voltage battery or batteries in the system.

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.

The present invention provides a heat suppressing alkaline storage battery including a positive electrode lead having a downsized portion that incorporates a PTC thermistor. A battery includes a positive electrode lead having a first lead half body, a second lead half body, and a PTC thermistor, the first and second lead half bodies overlap end portions formed in a portion where the first and second lead half bodies overlap with each other, the overlap end portions being larger than the PTC thermistor as viewed from a plane and being in contact with the PTC thermistor, the PTC thermistor is fitted in a fitting recessed portion formed in the overlap end portion of the first lead half body, and an exposed portion of the PTC thermistor is covered with a protective material.

A PTC device as well as an electrical device such as a battery pack or a dry-cell type secondary cell containing a PTC device and a secondary cell is made more compact. The PTC device includes (1) a PTC component including a laminar polymer PTC element having an electrically conductive filler and a polymer material, and a metal electrode disposed on a surface of each side of the polymer PTC element; and (2) a lead positioned at least in part on the metal electrode of the PTC component, and connected to the metal electrode by an electrically conductive material An exposed part of the electrically conductive material is covered by a protective member including a polypropylene resin, a nylon resin or an epoxy resin.

A protection circuit module which is welded to a connection tab and a PTC device without affecting a printed circuit board, and a battery pack including the same are provided. One embodiment of the present invention provides a battery pack having a bare cell and a protection circuit module electrically connected to the bare cell. The protection circuit module includes a printed circuit board, a connection tab positioned on a bottom surface of the printed circuit board, and a positive temperature coefficient (PTC) device electrically connected to the connection tab. The PTC device has a first lead coupled to a bottom surface of the connection tab, a PTC body electrically connected to the first lead, and a second lead electrically connected to the PTC body.

The present application relates to a positive electrode plate and an electrochemical device. The positive electrode plate includes a current collector, a positive active material layer and a safety coating disposed between the current collector and the positive active material layer, the safety coating including a polymer matrix and a conductive material, wherein the polymer matrix is fluorinated polyolefin and/or chlorinated polyolefin, and when the safety coating and the positive active material layer are collectively referred to as a positive film layer, the positive film layer includes Na ions and/or K ions at a content of 100 ppm or more, and has an absorption peak at 1646 cm.sup.−1 in infrared absorption spectrum. The positive electrode plate may improve safety performance at elevated temperature of the electrochemical device by quickly disconnecting the circuit at high temperature conditions or when an internal short circuit occurs.

A secondary battery includes: an electrode assembly; a sheet-type exterior configured to accommodate the electrode assembly; and a plurality of temperature sensing parts provided adjacent to the exterior to sense a temperature of a plurality of areas, respectively, of the exterior, wherein at least one of the plurality of temperature sensing parts includes: a positive temperature coefficient (PTC) element; and a negative temperature coefficient (NTC) element.

An electrode for solid-state batteries, comprising a PTC resistor layer, and a solid-state battery comprising the electrode. The electrode may be an electrode for solid-state batteries, wherein the electrode comprises an electrode active material layer, a current collector and a PTC resistor layer disposed between the electrode active material layer and the current collector; wherein the PTC resistor layer contains an electroconductive material, an insulating inorganic substance and a polymer; and wherein a porosity of the PTC resistor layer is from 5% to 13%.

The present application relates to a positive electrode plate, an electrochemical device and a safety coating. The positive electrode plate comprises a current collector, a positive active material layer and a safety coating disposed between the current collector and the positive active material layer, the safety coating comprising a fluorinated polyolefin and/or chlorinated polyolefin polymer matrix, a conductive material and an inorganic filler. The positive electrode plate can quickly disconnect circuit when the electrochemical device (such as a capacitor, primary battery, or secondary battery, and the like) is in a high temperature condition or an internal short circuit occurs, thereby improving high temperature safety performance of the electrochemical device.