Electrochemical devices that include porous layers, and associated methods, are generally described. In certain cases, the electrochemical device includes a first layer (e.g., a porous coating containing nanoparticles) between an anode and a separator, and a second layer (e.g., another porous coating containing nanoparticles) between a cathode and the separator. The first layer and/or the second layer may have a relatively high porosity, even after the application of an applied pressure to the electrochemical device. The presence of the first layer and the second layer in the electrochemical device may mitigate the occurrence of certain problematic phenomena during cycling of the electrochemical device.

The present disclosure provides a method for forming a solid-state battery. The method includes stacking two or more cell units, where each cell unit is formed by substantially aligning a first electrode and a second electrode, where the first electrode includes one or more first electroactive material layers disposed on or adjacent to one or more surfaces of a releasable substrate and the second electrode includes one or more second electroactive material layers disposed on or adjacent to one or more surfaces of a current collector; disposing an electrolyte layer between exposed surfaces of the first electrode and the second electrode; and removing the releasable substrate to form the cell unit.

The present disclosure provides a method for making a solid-state argyrodite electrolyte represented by Li.sub.6PS.sub.5X (where X is selected from chloride, bromide, iodine, or a combination thereof) having an ionic conductivity greater than or equal to about 1.0×10.sup.−4 S/cm to less than or equal to about 10×10.sup.−3 S/cm at about 25° C. The method may include contacting a first suspension and a first solution to form a precursor, where the first suspension is a Li.sub.3PS.sub.4 suspension including an ester solvent and the first solution is a Li.sub.2S and LiX (where X is selected from chloride, bromide, or iodine, or a combination thereof) solution including an alcohol solvent; and removing the ester solvent and the alcohol solvent from the precursor to form the solid-state argyrodite electrolyte.

A negative electrode for a lithium secondary battery, a method for preparing a negative electrode for a lithium secondary battery, and a lithium secondary battery including the negative electrode. The negative electrode for a lithium secondary battery includes a negative electrode current collector layer, a first negative electrode active material layer on one surface or both surfaces of the negative electrode current collector layer, and a second negative electrode active material layer on a surface opposite to a surface of the first negative electrode

A fuel cell assembly includes multiple fuel cells that are electrically coupled. Each fuel cell includes an electrolyte, an anode, and a cathode that can be fabricated from decorated or non-decorated carbon particles. The carbon particles can be produced by a methane dissociating reactor that converts methane into solid carbon and hydrogen. The electrolyte particles form an electrolyte structure that has a pattern of grooves on the anode and cathode facing surfaces. The electrolyte structure is sintered with microwave energy to fuse the adjacent electrolyte particles at contact points. The anode and cathode layers are deposited on opposite sides of the electrolyte and sintered. The anode and cathode layers are then processed to form multiple electrically fuel cells. The anode layers of the fuel cells are electrically coupled with interconnects to cathode layers of the adjacent fuel cells.

A coated cathode active material, a method of preparing the same, and a cathode and a non-aqueous electrolyte secondary battery, each including the same, the coated cathode active material including: a cathode active material particle and a coating layer on a surface of the cathode active material particle, the coating layer including LiAlF.sub.4, LiF, and Li.sub.3AlF.sub.6.

The present invention provides an active electrode material comprising a mixture of (a) at least one niobium oxide and (b) at least one mixed niobium oxide; wherein the mixed niobium oxide has the composition M1.sub.aM2.sub.1-aM3.sub.bNb.sub.12-bO.sub.33-c-dQ.sub.d, wherein: M1 and M2 are different; M1 is selected from Mg, Ca, Sr, Y, La, Ce, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, Cd, B, Al, Ga, In, Si, Ge, Sn, Pb, P, Sb, Bi and mixtures thereof; M2 is Mo or W; M3 is selected from Mg, Ca, Sr, Y, La, Ce, Ti, Zr, Hf, V, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, Cd, B, Al, Ga, In, Si, Ge, Sn, Pb, P, Sb, Bi, and mixtures thereof; Q is selected from F, Cl, Br, I, N, S, Se, and mixtures thereof; 0≤a<0.5; 0≤b≤2; −0.5≤c≤1.65; 0≤d≤1.65; one or more of a, b, c and d does not equal zero; and when a, b, and d equal zero, c is greater than zero. Such materials are of interest as active electrode materials in lithium-ion or sodium-ion batteries.

A composite cathode active material represented by Li.sub.x(Co.sub.1−wM1.sub.w).sub.yPO.sub.4 (Formula 1) having an olivine structure, wherein a unit-cell volume of the composite cathode active material is in a range of about 283 Å.sup.3 to about 284.6 Å.sup.3. A cathode including the composite cathode active material, and a secondary battery including the composite cathode active material are also disclosed.

In Formula 1, M1 includes i) at least one of Sc, Ti, V, Cr, Cu, or Zn, and optionally at least one of Fe or Ni, and 0.9≤x≤1.1, 0.9≤y≤1.1, and 0<w≤0.3.

In various examples, a functionalized cross-linked polymer network includes a plurality of cross-linked multifunctional trione triazine groups, a plurality of disulfide groups, a plurality of cross-linked multifunctional ether groups, a plurality of cross-linked multifunctional polyether groups, or a combination thereof, a plurality of crosslinking multifunctional polyether groups, and a plurality of dangling groups, where individual cross-linked multifunctional trione triazine groups and/or cross-linked multifunctional disulfide groups and/or cross-linked multifunctional ether groups and/or cross-linked multifunctional polyether groups and individual crosslinking multifunctional polyether groups are connected by one or more covalent bond(s) and individual dangling groups may be connected to the network by a covalent bond. At least a portion of or all of the dangling groups may be halogenated. A functionalized cross-linked polymer network may be made by polymerization (e.g., Thiol-ene reach on(s)) of one or more functionalized monomer(s) and one or more multifunctional monomer(s).

In fields related to battery cathode material technologies, a nano-silicon composite material and a preparation method thereof, an electrode material, and a battery are provided to resolve large volume expansion of a cathode material of a battery and a serious side reaction with an electrolyte. The nano-silicon composite material includes a core, a first coating layer, and a second coating layer. The core includes a nano-silicon crystal. The first coating layer covers a surface of the core. The first coating layer is of a porous structure. A material of the first coating layer includes bisilicate and silicon oxide in a deoxidized state. The second coating layer covers a surface of the first coating layer. A material of the second coating layer includes silicon dioxide in a deoxidized state.