Abstract: A secondary battery according to an embodiment of the present disclosure includes an electrode assembly to which an electrode lead is attached; a case accommodating the electrode assembly so that a portion of the electrode lead is exposed to the outside; a sealing portion formed in the case to seal the electrode assembly; and a lead film covering a portion of an outer surface of the electrode lead and interposed between the electrode lead and the sealing portion, wherein the electrode lead includes a first region not corresponding to the lead film and exposed to the outside of the case, a second region corresponding to the lead film, and a third region not corresponding to the lead film and not exposed to the outside of the case, wherein a separation groove may be located in the third region.

Abstract: An improved method for polymerizing one or more polyolefins in the presence of a transition metal catalyst in at least one gas phase fluidized bed reactor, the improvement comprises generating at least one low frequency, high pressure sound wave inside a reactor system, which wave has sufficient frequency and pressure to dislodge and/or prevent particle build-up on interior surfaces of the reactor system.

Abstract: An improved method for polymerizing one or more polyolefins in the presence of a transition metal catalyst in at least one gas phase reactor having an expanded section, the improvement comprising generating a tangential flow of gas or gas-solids in the expanded section of the gas phase reactor to reduce fines entrainment into the gas cycle system and to reduce or remove solid particle build-up on one or more interior surfaces of the expanded section of the reactor.

Abstract: A method for reducing sheeting during polymerization of alpha-olefins in a fluidized bed employing catalysts prone to cause sheeting which comprises feeding a material carrying a static electric charge opposite to the static charge in said bed, said opposite charge of said material being generated by passing said material in contact with a surface adapted to impart said static electric charge to said material opposite the charge existing in said bed.

Abstract: A method for reducing sheeting during polymerization of an alpha-olefin by feeding either a positive charge generating (MgO, ZnO, Al.sub.2 O.sub.3, CuO, and mixtures thereof) or a negative charge generating (V.sub.2 O.sub.5, SiO.sub.2, TiO.sub.2, Fe.sub.2 O.sub.3, and mixtures thereof) inorganic chemical additive to the reactor responsive to particular static levels in the reactor. The chemical additive is added in amounts which substantially neutralizes the electrostatic charge in the reactor.