According to one embodiment, a secondary battery is provided. The secondary battery includes a negative electrode including a negative electrode current collector, a negative electrode terminal electrically connected to the negative electrode current collector, a joint electrically connecting the negative electrode terminal and the negative electrode current collector, and a water repellent layer covering the joint. The joint is covered with the inner surface of the water repellent layer. A contact angle with respect to water on an outer surface of the water repellent layer satisfies 80.

A device for storing electrical energy is disclosed. The device includes an electrochemical cell having a cathode chamber for holding a liquid cathode material and an anode chamber for holding a liquid anode material. The cathode and anode chambers are separated by a solid electrolyte, wherein the solid electrolyte is surrounded by a planar construction having openings, through which the cathode material can flow. The planar construction is made of an electrically conductive material. The cathode chamber includes at least one segment, wherein each segment has a jacket composed of an electrically conductive material and the jacket is fastened to the planar construction having openings in a fluid-tight and electrically conductive manner and wherein each segment is filled with a porous felt or a porous material different from porous felt. A method for assembling and starting up the device and a method for operating the device is also disclosed.

A partition wall includes: a partition-wall body arranged within a metallic cathode container, which includes a cylinder-shaped cap communicating the inside with the outside, having a plate shape, which includes: an anode chamber at around the central site in the thickness direction; and a through bore, and made of beta-alumina; and a nipple-shaped head formed integrally with the partition-wall body, including a passage bore which is communicated with the anode chamber by way of the through bore, and attached air-tightly to the cap, and made of a ceramic material.

A sodium-sulfur battery includes a partition wall formed of a solid electrolyte, a cathode chamber formed on one of opposite sides of the partition wall, an anode chamber formed on another one of the opposite sides of the partition wall, sulfur accommodated in the cathode chamber, sodium some of which is accommodated in the anode chamber, a sodium container accommodating most of remaining sodium, and a communication passage communicating the anode chamber with the sodium container, and including a finely-perforated portion extending into the sodium container and opening inside the sodium container. Moreover, the communication passage further includes a shutoff portion for closing the communication passage itself.

According to one embodiment, a secondary battery is provided. The secondary battery includes a negative electrode including a negative electrode current collector, a negative electrode terminal electrically connected to the negative electrode current collector, a joint electrically connecting the negative electrode terminal and the negative electrode current collector, and a water repellent layer covering the joint. The joint is covered with the inner surface of the water repellent layer. A contact angle with respect to water on an outer surface of the water repellent layer satisfies 80.

The invention relates to an electrode unit for an electrochemical device, comprising a solid electrolyte (3) and a porous electrode (7), the solid electrolyte (3) dividing a compartment for cathode material and a compartment for anode material and the porous electrode (7) being extensively connected to the solid electrolyte (3), with a displacer (23) being accommodated in the anode material compartment, where the displacer (23) is manufactured from a stainless steel or from graphite foil and bears resiliently against the internal geometry of the solid electrolyte (3) in such a way that the displacer (23) does not contact the solid electrolyte over its full area, or with the displacer comprising an outer shell (62) of stainless steel or graphite, and a core (64) of a nonferrous metal, the nonferrous metal being thermoplastically deformable at a temperature which is lower than the temperature at which the stainless steel is thermoplastically deformable, and where for production the shell (62) of stainless steel or graphite is pressed onto the solid electrolyte (3) by introduction and heating of the nonferrous metal, and on cooling forms a gap between solid electrolyte (3) and shell (62) of stainless steel.

An object is to provide a plate-like partitioning wall allowing permeation of sodium ions therethrough and having high safety and durability. A plate-like partitioning wall 2 of the present invention is formed from a solid electrolyte allowing permeation of sodium ions therethrough. The plate-like partitioning wall 2 has a plate-like shape having, in a center part in the thickness direction thereof, a negative electrode chamber 20 to which molten sodium is supplied. This negative electrode chamber 20 is formed as a foil-like space extending in two-dimensional directions or as a pore-like space extending in two-dimensional directions in a net-like shape. The negative electrode chamber 20 of this plate-like partitioning wall 2 is formed as a thin foil-like space or as a fine pore-like space, and thus, the amount of molten sodium stored therein is very small. Therefore, even when this plate-like partitioning wall 2 is broken and reaction with molten sulfur occurs, the amount of heat generation is small, ignition is not caused, and thus, safety is high. The burn-out pattern and the organic matter powder forming the negative electrode chamber may also be those that are thin or fine. Thus, a small crack or the like is less likely to occur in the compacted body, and durability of the plate-like partitioning wall is high and manufacture thereof is facilitated.