Abstract: A device for protecting a cell is described comprising a cell body arranged in a container which has opening and closing means to open and close the cell body from the exterior atmosphere of the container. The device also has a sensor for sensing an impact to the cell body. When the impact is above a predetermined value, a barrier fluid is sprayed into the interior of the container. The opening and closing means of the container is operated in response to the spraying of the barrier fluid.

Abstract: In order to improve the charge-discharge energy density of a lithium secondary cell with a nonaqueous electrolyte having such a construction that a metallic compound capable of occluding or releasing lithium is used as an electrode active material, lithium or a lithium alloy is used as a negative electrode material and a solution of a lithium salt is used as an electrolyte, the microstructure of the metallic compound is rendered acicular. Further, a lithium-containing metallic compound grown into such a columnar form that has the angle .THETA. to the normal of the surface of the substrate of 0.degree..ltoreq..THETA.<90.degree. is used as the electrode active material.