A sulfide solid electrolyte containing the following (A) and (B): (A) a sulfide solid electrolyte having an argyrodite-type crystal structure; and (B) a sulfide solid electrolyte having a crystal structure different from the argyrodite-type crystal structure of the above-mentioned (A).

Articles and methods including additives in electrochemical cells, are generally provided. As described herein, such electrochemical cells may comprise an anode, a cathode, an electrolyte, and optionally a separator. In some embodiments, at least one of the anode, the cathode, the electrolyte, and/or the optional separator may comprise an additive and/or additive precursor. For instance, in some cases, the electrochemical cell comprises an electrolyte and an additive and/or additive precursor that is soluble with and/or is present in the electrolyte. In some embodiments, the additive precursor comprises a disulfide bond. In certain embodiments, the additive is a carbon disulfide salt. In some cases, the electrolyte may comprise a nitrate.

Electrochemical systems for mitigating or reducing the release of undesirable by-products of electrochemical cells are provided. These systems may be particularly relevant to the sequestering of hydrogen sulfide gas in solid state electrochemical cells with sulfide-based electrolytes. Some of the systems include an integrated hydrogen sulfide eliminating layer or microspheres containing a hydrogen sulfide eliminating material adjacent to one or more electrochemical cells and within a containment structure.

The present disclosure provides an electrolyte system for an electrochemical cell that cycles lithium ions. The electrolyte system may include an aliphatic fluorinated disulfonimide lithium salt in a mixture of organic solvents. The mixture of organic solvents may include a first solvent and a second solvent. The first solvent may include an ether solvent, a carbonate solvent, or a mixture of ether and carbonate solvents. The second solvent may include a fluorinated ether. A molar ratio of the aliphatic fluorinated disulfonimide lithium salt to the first solvent may be greater than or equal to about 1:1.2 to less than or equal to about 1:2. A molar ratio of the first solvent to the second solvent may be greater than or equal to about 1:1 to less than or equal to about 1:4.

An electrode material for a lithium ion secondary battery and method of forming the same, the electrode material including composite particles, each composite particle including: a primary particle including an electrochemically active material; and an envelope disposed on the surface of the primary particle. The envelope includes turbostratic carbon having a Raman spectrum having: a D band having a peak intensity (I.sub.D) at wave number between 1330 cm.sup.-1 and 1360 cW.sup.-1; a G band having a peak intensity (I.sub.G) at wave number between 1530 cm.sup.-1 and 1580 cm.sup.-1; and a 2D band having a peak intensity (I.sub.2D) at wave number between 2650 cm.sup.-1 and 2750 cm.sup.-1. In one embodiment, a ratio of I.sub.D/I.sub.G ranges from greater than zero to about 1.1, and a ratio of 1.sub.2D/I.sub.G ranges from about 0.4 to about 2.

The invention relates to Chevrel-phase materials and methods of preparing these materials utilizing a precursor approach. The Chevrel-phase materials are useful in assembling electrodes, e.g., cathodes, for use in electrochemical cells, such as rechargeable batteries. The Chevrel-phase materials have a general formula of Mo.sub.6Z.sub.8 (Z=sulfur) or Mo.sub.6Z.sup.1.sub.8-yZ.sup.2.sub.y (Z.sup.1=sulfur; Z.sup.2=selenium), and partially cuprated Cu.sub.1Mo.sub.6S.sub.8 as well as partially de-cuprated Cu.sub.1-xMg.sub.xMo.sub.6S.sub.8 and the precursors have a general formula of M.sub.xMo.sub.6Z.sub.8 or M.sub.xMo.sub.6Z.sup.1.sub.8-yZ.sup.2.sub.y, M=Cu. The cathode containing the Chevrel-phase material in accordance with the invention can be combined with a magnesium-containing anode and an electrolyte.

Lithium-ion batteries are provided that variously comprise anode and cathode electrodes, an electrolyte, a separator, and, in some designs, a protective layer. In some designs, at least one of the electrodes may comprise a composite of (i) Li2S and (ii) conductive carbon that is embedded in the core of the composite. In some designs, the protective layer may be disposed on at least one of the electrodes via electrolyte decomposition. Various methods of fabrication for lithium-ion battery electrodes and particles are also provided.

A sulfide solid electrolyte that contains lithium, phosphorus, sulfur, chlorine and bromine, wherein in powder X-ray diffraction analysis using CuKα rays, it has a diffraction peak A at 2θ=25.2±0.5 deg and a diffraction peak B at 2θ=29.7±0.5 deg, the diffraction peak A and the diffraction peak B satisfy the following formula (A), and a molar ratio of the chlorine to the phosphorus “c (Cl/P)” and a molar ratio of the bromine to the phosphorus “d (Br/P)” satisfies the following formula (1):
1.2<c+d<1.9  (1)
0.845<S.sub.A/S.sub.B<1.200  (A) where S.sub.A is an area of the diffraction peak A and S.sub.B is an area of the diffraction peak B.

Here is described an aluminum-ion battery technology having an electrolyte comprising an aluminum trichloride (Al—Cl3)/trimethylamine hydrochloride ionic liquid, aluminum metal as the anode material, and a compatible cathode active material. A wide variety of applications ranging from energy storage in consumer electronics to electric vehicles and to grid storage is also considered.

The present invention provides coated metal sulfide particles comprising a metal sulfide that is partially or totally coated with a coating layer containing a metal oxide, the metal sulfide having a composition ratio of sulfur to a metal (S/M.sup.1) of 2.1 to 10 in terms of the molar ratio. The coated metal sulfide particles are a material that improves charge-and-discharge cycle characteristics without reducing the initial capacity.