An electrochemical apparatus includes an electrode assembly. The electrode assembly includes a first electrode plate and a first tab group electrically connected to the first electrode plate, and an end of the electrode assembly includes a reusable region. The first electrode plate includes a first region located at an end of the first electrode plate and a second region connected to the first region, a thickness of the first region is less than a thickness of the second region, and the first region is disposed within the reusable region. The first tab group includes a first connecting portion located at an end of a first tab and a first bending portion connected to the first connecting portion and located on a side face of the electrode assembly, the first bending portion is disposed within the reusable region.

The present application relates to a separator, comprising a substrate and a coating formed on at least one surface of the substrate; wherein the coating comprises inorganic particles and organic particles, the organic particles comprise first organic particles and second organic particles; the first organic particles and the second organic particles are embedded in the inorganic particles and form protrusions on the surface of the coating; the first organic particles have a number-average particle size of >10 μm, and the second organic particles have a number-average particle size of 2 μm-10 μm. The present application also relates to a secondary battery comprising the separator, a device comprising the secondary battery and a method for preparing the separator.

Disclosed herein are a multilayer separator for a lithium secondary battery capable of preventing an internal short-circuit due to growth of lithium dendrite, and a method of manufacturing the same.

Embodiments described herein relate to electrodes and electrochemical cells with positive temperature coefficient coatings and methods of producing the same. In some embodiments, an electrode can include a layer of a film material, a positive temperature coefficient (PTC) coating disposed in the layer of film material. The PTC material resists a flow of current through at least a portion of the PTC material when a temperature of the at least a portion of the PTC material exceeds a threshold value. The electrode further includes an electrode material disposed on the PTC material. In some embodiments, the electrode can further include an electrode tab coupled to the PTC material and the electrode film. In some embodiments, the PTC material can include a conductive polymer. In some embodiments, the electrode material can include a semi-solid and/or a binderless electrode material.

A multilayer porous membrane with two exterior layers and at least one interior layer. The average pore size of the interior layer is greater than that of either of the two exterior layers. The multilayer porous membrane may be used, for example, as or as part of a battery separator. Compared to prior multilayer porous membranes for battery separators, the multilayer porous membrane herein may exhibit at least one of improved thermal properties, improved anti-metal contamination properties, improved ease of manufacture, and combinations thereof.

An electrolytic solution includes a compound represented by Formula I-A and a compound represented by Formula II-A. In Formula I-A, A.sup.11, A.sup.12, and A.sup.13 are each independently selected from Formula (I-A1) and Formula (I-A2). In Formula I-A, n is a positive integer from 1 to 8. When n>1, the plurality of A.sup.11 structures are identical or different. At least two of the A.sup.11, A.sup.12, or A.sup.13 are selected from I-A2. In Formula II-A, Q is independently selected from Formula (II-A1) and Formula (II-A2). In Formula II-A, m is 1 or 2. R.sup.11, R.sup.12, R.sup.13, R.sup.21, R.sup.22, and R.sup.23 are each independently selected from a covalent single bond, a substituted or unsubstituted C.sub.1 to C.sub.10 alkylidene and heterocyclyl, a substituted or unsubstituted C.sub.2 to C.sub.10 alkenyl and alkynyl, a substituted or unsubstituted C.sub.6 to C.sub.10 aryl, a substituted or unsubstituted C.sub.3 to C.sub.10 alicyclic hydrocarbyl, and a substituted or unsubstituted heteroatom-containing functional group, in which a substituent for substitution is halogen.

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A battery cell may include an electrolyte, a first electrode including a first electrode layer and a first current collector, a second electrode including a second electrode layer and a second current collector, a separator interposed between the first electrode and the second electrode, and at least one protective layer. For example, a protective layer may be interposed between the first electrode layer and the first current collector, the second electrode layer and the second current collector, the separator and the first electrode, and/or the separator and the second electrode. When activated, the one or more protective layers may reduce or interrupt current flow through the battery cell. The composition of the one or more protective layers may include one or more small molecule additives to increase its stability and conductivity, thus improving the performance as well as the safety profile of the battery cell.

An electrode layer for an all-solid state battery contains an electrode active material, a sulfide solid electrolyte, and a residual liquid, where the residual liquid has a δ.sub.P of less than 2.9 MPa.sup.½ in a Hansen solubility parameter and a boiling point of 190° C. or higher.

A highly safe power storage system is provided. If n (n is an integer over or equal to three) secondary batteries are used in a vehicle such as an electric vehicle, a circuit configuration is used with which the condition of each secondary battery is monitored using an anomaly detection unit; and if an anomaly such as a micro-short circuit is detected, only the detected anomalous secondary battery is electrically separated from the charging system or the discharging system. At least one microcomputer monitors anomalies in n secondary batteries consecutively, selects the anomalous secondary battery or the detected secondary battery which causes an anomaly, and gives an instruction to bypass the secondary battery with each switch.

A use, in an electrolyte for a battery, of an additive which includes at least one organocatalyst. Also, a method of preventing the contact between the anode and residual water in a battery and/or reducing the level of gas in a battery. Moreover, an electrolyte for a battery, including an additive which includes at least one organocatalyst. Moreover, a battery including an electrolyte which includes an additive which comprises at least one organocatalyst.