A method of manufacturing an electrode for an electrochemical cell includes providing an admixture including an electroactive material, a binder, and a solvent. The method further includes rolling the admixture to form a sheet and forming a multi-layer stack from the sheet. The method further includes forming an electrode film precursor by performing a plurality of sequential rollings, each including rolling the stack through a first gap. The plurality of sequential rollings includes first and second rollings. In the first rolling, the stack is in a first orientation. In the second rolling, the stack is in a second orientation different from the first orientation. The method further includes forming an electrode film by rolling the electrode film precursor through a second gap less than or equal to the first gap. The method further includes drying the electrode film to remove at least a portion of the solvent.

The present disclosure relates to high capacity (e.g., areal capacity greater than about 4 mAh/cm.sup.2 to less than or equal to about 50 mAh/cm.sup.2) electrodes for electrochemical cells. An example electrode may include a current collector (e.g., meshed current collector) and one or more electroactive material layers having thicknesses greater than about 150 μm to less than or equal to about 5 mm. The electroactive material layers may each include lithium manganese iron phosphate (LiMn.sub.xFe.sub.1-xPO.sub.4, where 0≤x≤1) (LMFP). The electrode may further include one or more electronically conductive adhesive layers disposed between the current collector and the electroactive material layers. The adhesive layers may include one or more polymer components and one or more conductive fillers. The electroactive material layers may be gradient layers, where sublayers closer to the current collector has a lower porosity than layers further from the current collector.

The present disclosure provides supercapacitors that may avoid shortcomings of current energy storage technology. Provided herein are materials and fabrication processes of such supercapacitors. In some embodiments, an electrochemical system comprising a first electrode, a second electrode, wherein at least one of the first electrode and the second electrode comprises a three dimensional porous reduced graphene oxide framework.

The present disclosure provides supercapacitors that may avoid shortcomings of current energy storage technology. Provided herein are materials and fabrication processes of such supercapacitors. In some embodiments, an electrochemical system comprising a first electrode, a second electrode, wherein at least one of the first electrode and the second electrode comprises a three dimensional porous reduced graphene oxide framework.

Provided are a MoS.sub.xO.sub.y/carbon nanocomposite material, a preparation method therefor and a use thereof. In the MoS.sub.xO.sub.y/carbon nanocomposite material, 2.5≤x≤3.1, 0.2≤y≤0.7, and the mass percent of MoS.sub.xO.sub.y is 5%-50% based on the total mass of the nanocomposite material. When the MoS.sub.xO.sub.y/carbon nanocomposite material is used as a catalyst for an electrocatalytic hydrogen evolution reaction, the current density is 150 mA/cm.sup.2 or more at an overpotential of 300 mV. The difference between this performance and the performance of a commercial 20% Pt/C catalyst is relatively small, or even equivalent; and this performance is far better than the catalytic performance of an existing MOS.sub.2 composite material. The MoS.sub.xO.sub.y/carbon nanocomposite material also has a good catalytic stability, and after 8,000 catalytic cycles, the current density thereof is only decreased by 3%, thus exhibiting a very good catalytic performance and cycle stability.

Provided are a MoS.sub.xO.sub.y/carbon nanocomposite material, a preparation method therefor and a use thereof. In the MoS.sub.xO.sub.y/carbon nanocomposite material, 2.5≤x≤3.1, 0.2≤y≤0.7, and the mass percent of MoS.sub.xO.sub.y is 5%-50% based on the total mass of the nanocomposite material. When the MoS.sub.xO.sub.y/carbon nanocomposite material is used as a catalyst for an electrocatalytic hydrogen evolution reaction, the current density is 150 mA/cm.sup.2 or more at an overpotential of 300 mV. The difference between this performance and the performance of a commercial 20% Pt/C catalyst is relatively small, or even equivalent; and this performance is far better than the catalytic performance of an existing MOS.sub.2 composite material. The MoS.sub.xO.sub.y/carbon nanocomposite material also has a good catalytic stability, and after 8,000 catalytic cycles, the current density thereof is only decreased by 3%, thus exhibiting a very good catalytic performance and cycle stability.

An amorphous oxide-based positive electrode active material that is a production material of a positive electrode for an all-solid secondary battery, wherein the amorphous oxide-based positive electrode active material (i) comprises an alkali metal selected from Li and Na; a second metal selected from Co, Ni, Mn, Fe, Cr, V, Cu, Ti, Zn, Zr, Nb, Mo, Ru and Sn; an ionic species selected from phosphate ion, sulfate ion, borate ion, silicate ion, aluminate ion, germanate ion, nitrate ion, carbonate ion and halide ion; and an oxygen atom (except for the oxygen atom constituting the ionic species); (ii) contains at least an amorphous phase; and (iii) is a production material of a positive electrode with a thickness of 20 μm or more.

An amorphous oxide-based positive electrode active material that is a production material of a positive electrode for an all-solid secondary battery, wherein the amorphous oxide-based positive electrode active material (i) comprises an alkali metal selected from Li and Na; a second metal selected from Co, Ni, Mn, Fe, Cr, V, Cu, Ti, Zn, Zr, Nb, Mo, Ru and Sn; an ionic species selected from phosphate ion, sulfate ion, borate ion, silicate ion, aluminate ion, germanate ion, nitrate ion, carbonate ion and halide ion; and an oxygen atom (except for the oxygen atom constituting the ionic species); (ii) contains at least an amorphous phase; and (iii) is a production material of a positive electrode with a thickness of 20 μm or more.

A method for preparing iron phosphide (FeP), a positive electrode of a lithium secondary battery including iron phosphide (FeP), for instance, prepared using the method, and a lithium secondary battery including the same. In the lithium secondary battery including the positive electrode using iron phosphide (FeP), the iron phosphide (FeP) adsorbs lithium polysulfide (LiPS) produced during a charge and discharge process of the lithium secondary battery, which is effective in increasing charge and discharge efficiency and enhancing lifetime properties of the battery.

The present disclosure relates to a composite material of formula (I): (LPS).sub.a(OIPC).sub.b wherein each of a and b is a mass % value from 1% to 99% such that a+b is 100%; (LPS) is a material selected from the group consisting of Li.sub.3PS.sub.4, Li.sub.7P.sub.3S.sub.11, Li.sub.10GeP.sub.2S.sub.11, and a material of formula (II): xLi.sub.2S.yP.sub.2S.sub.5.(100−x−y)LiX; wherein X is I, Cl or Br, each of x and y is a mass % value of from 33.3% to 50% such that x+y is from 75% to 100% and the total mass % of Li.sub.2S, P.sub.2S.sub.5 and LiX is 100%; and (OIPC) is a salt of a cation and a closo-borane cluster anion.