Abstract: A lithium secondary battery includes an electrode assembly including a cathode and an anode facing the cathode, a case accommodating the electrode assembly, an electrolyte accommodated in the case together with the electrode assembly, and an electrolyte storage unit inserted into the case to supply a supplementary replenishment. The electrolyte storage unit includes a first unit including a first body having a tubular structure and first holes formed through the first body, and a sub-unit including a tubular body and sub-holes formed through the tubular body. The sub-unit is inserted into the first unit so that the sub-holes are offset from the first holes.

Abstract: Provided is a lithium secondary battery including: a cathode including a cathode current collector and a cathode active material layer positioned on the cathode current collector; a nonaqueous electrolyte; and an anode, wherein the cathode active material layer includes a lithium transition metal oxide particle, and the lithium transition metal oxide particle contains a nickel (Ni) atom in an amount of 60 mol % or more with respect to a total of 100 mol % of transition metal atoms, and the nonaqueous electrolyte contains a polyethylene glycol-based polymer.

Abstract: An electrode for a lithium secondary battery includes a current collector, primer layer formed on a side of the current collector and includes a first conductive agent, a first binder and a first dispersant. Further, an active material layer is formed on a side of the primer layer disposed opposite to the current collector and includes an active material. Additionally, the lithium secondary battery includes a positive electrode, a negative electrode or both, a separator disposed between the positive electrode and the negative electrode and an electrolyte. The structural stability and adhesion of the electrode is improved, a ratio of a binder in the active material layer is reduced and the internal resistance is reduced.

Abstract: The present invention relates to a safety test apparatus of a battery cell. The safety test apparatus of the battery cell comprises: a jig on which the battery cell is disposed on a top surface thereof; and an impact member comprising an impact rod supported on the top surface of the battery cell and a striking weight disposed above the jig to freely drop toward the jig and strike the impact rod so that an impact is applied to the battery cell, wherein the striking weight is provided in a pair and comprises left and right striking parts that respectively strike two striking points, which are spaced apart from each other, of the impact rod and a connection part connecting the left and right striking parts to each other.

Abstract: The present invention relates to a safety test apparatus of a battery cell. The safety test apparatus of the battery cell comprises: a jig on which the battery cell is disposed on a top surface thereof; and an impact member comprising an impact rod supported on the top surface of the battery cell and a striking weight disposed above the jig to freely drop toward the jig and strike the impact rod so that an impact is applied to the battery cell, wherein the striking weight is provided in a pair and comprises left and right striking parts that respectivley strike two striking points, which are spaced apart from each other, of the impact rod and a connection part connecting the left and right striking parts to each other.

Abstract: An electrode for a lithium secondary battery includes a current collector, primer layer formed on a side of the current collector and includes a first conductive agent, a first binder and a first dispersant. Further, an active material layer is formed on a side of the primer layer disposed opposite to the current collector and includes an active material. Additionally, the lithium secondary battery includes a positive electrode, a negative electrode or both, a separator disposed between the positive electrode and the negative electrode and an electrolyte. The structural stability and adhesion of the electrode is improved, a ratio of a binder in the active material layer is reduced and the internal resistance is reduced.