The present disclosure provides a liquid detection sensor which has the general purpose usability and can prevent the deterioration of a metal-air battery being an electric power source even when being installed for a long term, and in which the metal-air battery being an electric power source can exhibit an excellent electric power generation performance. The liquid detection sensor has the metal-air battery having a positive electrode, a negative electrode, and an electrolytic solution-forming component positioned between the positive electrode and the negative electrode, wherein the electrolytic solution-forming component is enclosed in the inside of a resin-made bag; and a resin of the resin-made bag has dissolvability or dispersibility in a liquid being an object to be detected.

An aqueous secondary battery including: a positive electrode; a negative electrode; a separator; and an aqueous electrolytic solution including water and a metal salt represented by Chemical Formula 1 A.sub.xD.sub.y and having molality of about 5 M to about 40 M wherein in Chemical Formula 1, A is at least one metal ion selected from a sodium ion, a potassium ion, a magnesium ion, a calcium ion, a strontium ion, a zinc ion, or a barium ion, D is at least one type of atomic group ion selected from Cl.sup.−, SO.sub.4.sup.2−, NO.sub.3.sup.−, ClO.sub.4.sup.−, SCN.sup.−, CF.sub.3SO.sub.3.sup.−, C.sub.4F.sub.3SO.sub.3.sup.−, (CF.sub.3SO.sub.2).sub.2N.sup.−, AlO.sub.2.sup.−, AlCl.sub.4.sup.−, AsF.sub.6.sup.−, SbF.sub.6.sup.−, BR.sub.4.sup.−, and PO.sub.2F.sub.2.sup.−, and 0<x≤2, and 0<y≤2.

A nanofluid contact potential difference cell includes a cathode with a lower work function and an anode with a higher work function separated by a nanometer-scale spaced inter-electrode gap containing a nanofluid with intermediate work function nanoparticle clusters. The cathode comprises a refractory layer and a thin film of electrosprayed dipole nanoparticle clusters partially covering a surface of the refractory layer. A thermal power source, placed in thermal contact with the cathode, to drive an electrical current through an electrical circuit connecting the cathode and anode with an external electrical load in between. A switch is configured to intermittently connect the anode and the cathode to maintain non-equilibrium between a first current from the cathode to the anode and a second current from the anode to the cathode.

A method of forming a lithium or sodium foil for use as an electrode involves imposing a surface texturing that is predominately the {110} or {100} crystallographic orientation. For a Li {110} foil, a raw foil with a thickness of about 600 μm is heated to about 90° C. to randomize the crystallographic orientation and the foil is rolled to about 300 μm upon cooling. The rolled film is then scraped of about 50 μm of the lithium surface and heated to about 75° C. and rolled a second time to about 200 μm, and again cooled to room temperature. The cooled foil can be shaped into the electrode. The electrode can be employed in a battery to greatly extend the life of the battery relative to a lithium battery with a lithium anode that lacks the surface texturing. The alkali metal can be lithium electrochemically deposited on 3D scaffold such as carbon cloth with the deposited alkali metal maintaining the {110} texture.

Novel, rechargeable magnesium/magnesium sulfide batteries are disclosed therein, having energy density competitive with lithium batteries, high cycle life, and lower cost. Production method of stabilized MgS is also described, as well as various cells constructions.

Provided is an electrochemical device including a negative electrode, a positive electrode, and a separator disposed between the negative electrode and the positive electrode. In the electrochemical device, the negative electrode is an electrode containing magnesium, and is in contact with a fullerene analogue-containing layer containing a fullerene analogue. The electrolytic solution of the electrochemical device includes a solvent and a magnesium salt contained in the solvent.

Hybrid electrodes for batteries are disclosed having a protective electrochemically active layer on a metal layer. Other hybrid electrodes include a silicon salt on a metal electrode. The protective layer can be formed directly from the reaction between the metal electrode and a metal salt in a pre-treatment solution and/or from a reaction of the metal salt added in an electrolyte so that the protective layer can be formed in situ during battery formation cycles.

An electrochemical battery cell comprising an anode having a primary anode active material, a cathode, and an ion-conducting electrolyte, wherein the cell has an initial output voltage, Vi, measured at 10% depth of discharge (DoD), selected from a range from 0.3 volts to 0.8 volts, and a final output voltage Vf measured at a DoD no greater than 90%, wherein a voltage variation, (Vi−Vf)/Vi, is no greater than ±10% and the specific capacity between Vi and Vf is no less than 100 mAh/g or 200 mAh/cm.sup.3 based on the cathode active material weight or volume, and wherein the primary anode active material is selected from lithium (Li), sodium (Na), potassium (K), magnesium (Mg), aluminum (Al), zinc (Zn), titanium (Ti), manganese (Mn), iron (Fe), vanadium (V), cobalt (Co), nickel (Ni), a mixture thereof, an alloy thereof, or a combination thereof.

Described herein are electrodes, electrochemical cells, methods of making electrodes and methods of making electro-chemical cells. The electrodes described herein have an interface layer or material that can stabilize reversible alkali metal deposition. The interface material may correspond to or be a solid-electrolyte interphase that can allow alkali metal ions to transmit through and be deposited below the interface material. The interface material can prevent dendrite formation and/or decomposition of the electrolyte, enabling use of lithium metal safely in a secondary (i.e., rechargeable) electrochemical cell. The interface material may comprise a combination of one or more metals, one or more chalcogens, and one or more other elements or organic functional groups.

The present invention is directed to the modification of sodium electrochemical interfaces to improve performance of NaSICON-type ceramics in a variety of electrochemical applications. Enhanced mating of the separator-sodium interface by means of engineered coatings or other surface modifications results in lower interfacial resistance and higher performance at increased current densities, enabling the effective operation of molten sodium batteries and other electrochemical technologies at low and high temperatures.