A wireless charging system includes a first winding portion, a second winding portion which is disposed with an interval between the first winding portion and the second winding portion in an axis direction of the first winding portion, and a pair of magnetic members which are disposed so as to sandwich the first winding portion and the second winding portion in the axis direction. In this case, protrusion portions which protrude toward the other magnetic member are provided in one magnetic member. Also, the magnetic member is held so as to be able to move forward and backward toward the other magnetic member. As a result, since the coefficient of magnetic coupling between a transmitting unit and a receiving unit during charging is enhanced, a charging efficiency can be enhanced.

Disclosed herein are a positive electrode active material including at least one selected from among compounds represented by Formula 1 below and a lithium secondary battery including the same that is capable of improving lifetime characteristics and rate characteristics while exhibiting excellent safety: xLi.sub.2M.sub.yMn.sub.(1-y)O.sub.3-zA.sub.z*(1x)LiMO.sub.2-zA.sub.z (1), where M is at least one element selected from a group consisting of Ru, Mo, Nb, Te, Re, Ir, Pt, Cr, S, W, Os, and Po, M is at least one element selected from a group consisting of Ni, Ti, Co, Al, Mn, Fe, Mg, B, Cr, Zr, Zn, and second row transition metals, A and A are each independently a negative monovalent or divalent anion, and 0<x<1, 0.3<y<1, 0z<0.5, and 0z<0.5.

The present invention provides a battery module comprising: a cell assembly including a plurality of battery cells arrayed in a second direction different from a first direction while each cell axis is directed in the first direction; and an accommodation case configured to accommodate the cell assembly, wherein in the accommodation case, a suction hole configured to take a gas into a peripheral space located on a side of the cell assembly in the first direction and an exhaust hole configured to exhaust the gas having passed between the plurality of battery cells are provided in one surface of two surfaces that sandwich the cell assembly in the second direction, and a rib extending in the second direction is provided in the peripheral space.

A bridge link battery interface for a helmet accessory mounting system includes a housing enclosing a circuit and an electrical and mechanical coupling interface structured and operable to connect to an attachment point on the helmet accessory mounting system. A first battery interface is configured for detachable coupling to a first battery pack and a second battery interface configured for detachable coupling to a second battery pack. First and second electrical connector assemblies are disposed on the housing and electrically coupled to the circuit, wherein the circuit is operable to selectively electrically couple the first and second battery interfaces to the first and second electrical connector assemblies.