A composition comprising a graphitic carbon nitride material and a conductive carbon material coating may be used in electrodes or in batteries such as sodium ion batteries. The composition may be prepared using a method comprising the steps of providing a nitrogenous compound; adding a carbonaceous material to the nitrogenous compound to form a slurry; drying the slurry to form a coated mixture; and carbonizing the coated mixture.

Provided is a method of producing a multivalent metal-ion battery comprising an anode, a cathode, and an electrolyte in ionic contact with the anode and the cathode to support reversible deposition and dissolution of a multivalent metal, selected from Ni, Zn, Be, Mg, Ca, Ba, La, Ti, Ta, Zr, Nb, Mn, V, Co, Fe, Cd, Cr, Ga, In, or a combination thereof, at the anode, wherein the anode contains the multivalent metal or its alloy as an anode active material and the cathode comprises a cathode active layer of graphitic carbon particles or fibers that are coated with a protective material. Such a metal-ion battery delivers a high energy density, high power density, and long cycle life.

An anode material for an electrochemical cell comprises a matrix material:distributed material composite, which comprises one or more alkali metals and/or alkali earth metals. The distributed material may comprise a metal other than that of the matrix material, such as a transition and/or post transition metal. The anode material may be all or part of an anode for an electrochemical cell, which may further comprises a current collector and/or an SEI layer. The electrolyte may comprises an alkali metal and/or alkali earth metal and/or a transition metal and/or post transition metal containing electrolyte salt. The matrix material and/or the distributed material may comprise one or more of the metals of the electrolyte salt. All or part of the anode may be used as a substrate for electro-deposition of one or more matrix materials during charging and/or all or part of the anode may be used as a source of matrix material during discharging. The electrolyte may further comprise one or more electrolyte additives. The anode material may be produced by mixing a matrix material and distributed material and heating the mixture to selectively melt the matrix material to produce a matrix material:distributed material composite. The composite may be further chemically or mechanically processed to reduce the size of the distributed material and/or to increase the homogeneity of the matrix material:distributed material composite. The anode material, the anode or the electrochemical cell may be used in a device.

Provided is a metal-sulfur battery, comprising a positive electrode material, a negative electrode material and an electrolyte, the positive electrode material comprises one of elemental sulfur and S-based compound; the electrolyte comprises a solvent and an electrolyte salt; and the electrolyte salt comprises one or more salts represented by structural formulas 1-3:

##STR00001## wherein, R.sub.1 is selected from S or Se; R.sub.2 is selected from C, Si, Ge or Sn; M.sub.1 is selected from N, B, P, As, Sb or Bi; M.sub.2 is selected from Li, Na, K, Ru, Cs, Fr, Al, Mg, Zn, Be, Ca, Sr, Ba or Ra; R.sub.3 is selected from a carbon chain or an aromatic ring with part or all of hydrogen substituted by other elements or groups. The metal-sulfur battery provided by the disclosure can effectively solve the short circuit problem caused by metal dendrites on the negative electrode of existing metal-sulfur battery.

A low voltage electrochemical cell is provided that includes a metallic anode including an anode metal, a metallic cathode including a cathode metal, the metallic cathode further including a surface layer including an alloy of the anode metal and the cathode metal, an electrolyte disposed between the metallic anode and the metallic cathode, and a separator within the electrolyte or embedded with electrolyte. The electrochemical cell further includes a voltage stabilization electron current between said anode and said cathode, where the voltage stabilization electron current has an amperage capable of maintaining an open load circuit voltage of the electrochemical cell that varies by less than 10 percent over 10 hours or greater, optionally a month or greater, optionally over the cell lifetime, or a non-equilibrium anode metal/cathode metal ratio in the surface layer for 10 hours or greater, optionally a month or greater, optionally over the cell lifetime.

An electrode including an electrode active material and a mesoporous film coating at least a portion of the electrode active material is provided. The mesoporous film coats at least a portion of the electrode active material and includes M.sub.2SiO.sub.3, MAlO.sub.2, M.sub.2O—Al.sub.2O.sub.3—SiO.sub.2, or combinations thereof, where M is lithium (Li), sodium (Na), or a combination thereof. Methods of fabricating the electrode are also provided.

An electrolyte for a lithium-sulfur battery and the lithium-sulfur battery including the electrolyte, more particularly, an electrolyte for the lithium-sulfur battery including lithium salt, an organic solvent and an additive, wherein the additive includes an alkali metal salt-type ionomer. The electrolyte for the lithium-sulfur battery improves the migration characteristics of lithium ions and thus improves the capacity and life characteristics of the lithium-sulfur battery by including a polymer containing the alkali metal ion as an additive.

The present disclosure is generally related to separators for use in lithium metal batteries, and associated systems and products. Certain embodiments are related to separators that form or are repaired when an electrode is held at a voltage. In some embodiments, an electrochemical cell may comprise an electrolyte that comprises a precursor for the separator.

The invention provides novel high-energy density and low-cost flow electrochemical devices incorporating solid-flow electrodes, and further provides methods of using such electrochemical devices. Included are anode and cathode current collector foils that can be made to move during discharge or recharge of the device. Solid-flow devices according to the invention provide improved charging capability due to direct replacement of the conventional electrode stack, higher volumetric and gravimetric energy density, and reduced battery cost due to reduced dimensions of the ion-permeable layer.

The present technology provides rechargeable alkali metal-sulfur galvanic cells and batteries incorporating such cells as well as methods of using such cell and batteries. The present galvanic cells provide high specific energy and high power at lower cost than conventional alkali metal-sulfur cells.