A power storage device includes a module laminate including a plurality of power storage modules arranged in one direction; a pair of end plates respectively arranged at both ends of the module laminate in the one direction; a fastening bolt configured to fasten the pair of end plates together around the module laminate and apply a predetermined restraint load to the module laminate via the end plate; and a collar member including a through-hole allowing the fastening member to be inserted therethrough, the collar member being sandwiched by the pair of end plates around the module laminate. The through-hole of the collar member is eccentric with respect to a center axis of the collar member so as to approach a side where the module laminate is arranged.

A partition for an electrochemical apparatus, the electrochemical apparatus, and an electronic apparatus are provided, and the partition for the electrochemical apparatus is of ionic insulation and has an intermediate layer and packaging layers, where the packaging layers are located on upper and lower surfaces of the intermediate layer; and a temperature at which the packaging layers start to soften is at least 10° C. lower than a temperature at which the intermediate layer starts to soften. Through the partition that is obtained through lamination of at least three layers of composite films, ionic insulation and packaging reliability can be ensured.

A bipolar battery may comprise first, second, and third bipolar electrodes that are physically and electrically isolated from one another by intervening non-liquid electrolyte layers. Each of the bipolar electrodes may comprise a bipolar current collector including a first electroactive material layer connected to a first side thereof and a second electroactive material layer connected to a second side thereof. Each electroactive material layer may comprise at least one of: (i) a lithium ion battery positive electrode material, (ii) a lithium ion battery negative electrode material, and/or (iii) a capacitor electrode material. At least one of the electroactive material layers comprises a capacitor electrode material.

An electrochemical device including a bipolar current collector. The bipolar current collector is hermetically connected to an outer package. Cavities independent of each other are formed on two opposite sides of the bipolar current collector. Each cavity contains an electrode assembly and an electrolytic solution. An electrode active material is disposed on at least one surface of the bipolar current collector. Adjacent electrode assemblies are connected in series. The electrochemical device according to this application not only improves the safety of the electrochemical device, but the electrode active material on the surface of the bipolar current collector also participates in a reaction process in the electrochemical device, so that the electrochemical device achieves both a high-voltage output and a relatively high energy density.

A method for forming a bipolar battery assembly comprising: a) forming an electrode plate stack by stacking a plurality of electrode plates to create a plurality of electrochemical cells therebetween; b) applying the one or more membrane sheets to the one or more exterior surfaces such that the one or more membrane sheets conform to contours of the exterior surface and form a membrane of the bipolar battery assembly; and wherein the method includes one or more of the following: i) heating the one or more exterior surfaces of the electrode plate stack to form one or more preheated exterior surfaces prior to application of the one or more membrane sheets; ii) heating the one or more membrane sheets to form one or more heated membrane sheets prior to application of the one or more membrane sheets; and/or iii) drawing a vacuum from the electrode plate stack, after application of the one or more membrane sheets, to form fit the one or more membrane sheets to the one or more exterior surfaces to form the membrane. Heating may be found useful as preheating, simultaneous heating, and/or post heating in relation to the application of the one or more membrane sheets.

The battery pack includes: a first battery module and a second battery module each including multiple battery cells that are stacked together; and a cooler. The cooler is located between the first battery module and the second battery module, is configured to cool the first battery module and the second battery module, and includes an electrically conductive member.

A bipolar battery including a first electrochemical cell and a second electrochemical cell is provided.

A secondary battery for cycling between a charged and a discharged state, wherein a 2D map of the median vertical position of the first opposing vertical end surface of the electrode active material in the X-Z plane, along the length LE of the electrode active material layer, traces a first vertical end surface plot, EVP1, a 2D map of the median vertical position of the first opposing vertical end surface of the counter-electrode active material layer in the X-Z plane, along the length LC of the counter-electrode active material layer, traces a first vertical end surface plot, CEVP1, wherein for at least 60% of the length Lc of the first counter-electrode active material layer (i) the absolute value of a separation distance, SZ1, between the plots EVP1 and CEVP1 measured in the vertical direction is 1000 μm≥|SZ1|≥5 μm.

An electricity storage device according to one embodiment is an electricity storage device in which a plurality of bipolar electrodes in which a positive electrode layer is provided on one surface of a collector plate and a negative electrode layer is provided on the other surface of the collector plate are stacked via separators and includes a plurality of spacers arranged along peripheral edges of the collector plates between the respective collector plates adjacent to each other in a stacking direction and a resin frame covering outer peripheries of the plurality of spacers.

The power storage device includes power storage units arranged with a conductive plate interposed therebetween in the vertical direction, each of the power storage units includes an electrode stack including bipolar electrodes stacked with a separator interposed therebetween, and a sealing member provided around the electrode stack so as to seal a housing space formed between adjacent electrodes of the electrode stack. At least one of the power storage units is provided with an overhang member on an outer peripheral surface of the sealing member. The overhang member includes an inclined portion that extends from the outer peripheral surface of the sealing member toward the outside of the power storage unit and inclines downward as it leaves away from the outer peripheral surface of the sealing member, and a top portion formed at a lower end of the inclined portion.