A method for preparing an SEI (solid electrolyte interphase)-like film component additive, and an electrolyte solution comprising the SEI-like film component additive prepared by the method are provided. Compared with a conventional electrolyte solution (electrolyte solution without adding SEI-like film component additive), the electrolyte solution of the present application can prevent the loss of the effective ingredients caused by the dissolution of the SEI film on the negative electrode in the electrolyte solution during battery storage and use, and the electrolyte solution of the present application can also timely supplement the lost or damaged SEI film with effective ingredients, so that the damaged parts of the SEI film are quickly and timely supplemented.

The electrolyte for a lithium secondary battery includes: a lithium salt; a solvent; and a functional additive, wherein the functional additive includes: at least one high-voltage additive selected from a group consisting of lithium bis(phthalato)borate, represented by the following formula 1; hexafluoroglutaric anhydride, represented by the following formula 2; and phosphoric acid tris(2,2,2-trifluoroethyl)ester, represented by the following formula 3: ##STR00001##

The present invention provides a method of preparing an electrode for a lithium secondary battery which includes forming a first electrolyte layer by immersing an electrode current collector in a composition for forming the first electrolyte layer and applying a current, and forming a second electrolyte layer by immersing the electrode current collector having the first electrolyte layer formed thereon in a composition for forming the second electrolyte layer and applying a current, wherein one of the composition for forming the first electrolyte layer and the composition for forming the second electrolyte layer is a composition for forming an organic electrolyte layer, and another one is a composition for forming an inorganic electrolyte layer, and the composition for forming an inorganic electrolyte layer includes a compound represented by Formula 1.

The disclosure provides a solid-state battery including a cathode comprising a lithium-based conducting material having a porosity less than or equal to 6% and a surface roughness of equal to or less than 300 nm. The solid-state battery may also include an anode and a solid electrolyte between the cathode and the anode.

Provided is a positive electrode active material for nonaqueous electrolyte secondary batteries that suppresses the gelling of a positive electrode mixture material paste and has high weather resistance, a production method thereof, and the like. A method for producing a positive electrode active material for nonaqueous electrolyte secondary batteries includes cleaning a powder formed of a lithium-nickel composite oxide represented by a general formula Li.sub.zNi.sub.1-x-yCo.sub.xM.sub.yO.sub.2 where 0≤x≤0.35; 0≤y≤0.10; 0.95≤z≤1.10; and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al with an aqueous lithium carbonate solution and drying the cleaned powder.

There is described a direct carbon fuel cell system. The system includes fuel cells, each fuel cell having a porous fuel cell anode and a fuel cell cathode. The system further includes a molten carbonate electrolyte and a fuel supply apparatus for flowing a fuel slurry having carbon particles and a carbon carrier fluid to the fuel cell anodes in parallel. The carbon carrier fluid has a same composition as the molten carbonate electrolyte. An oxidant supply apparatus flows an oxygen-containing stream to the fuel cell cathodes in parallel. An electrolyte circulation apparatus circulates the molten carbonate electrolyte in contact with each of the fuel cells. During operation of the direct carbon fuel cell system to generate electric power, carbon is oxidized at the fuel cell anodes to produce carbon dioxide, and at the fuel cell cathodes oxygen and carbon dioxide react to produce carbonate ions.

Provided herein are energy storage devices high energy and power densities, cycle life, and safety. In some embodiments, the energy storage device comprise a non-flammable electrolyte that eliminate and/or reduce fire hazards for improved battery safety, with improved electrode compatibility with electrode materials.

An electrolyte for a lithium secondary battery includes an organic solvent in an amount ranging from 90 wt % to 96% based on a total weight of the electrolyte solution, a lithium salt in an amount ranging from 0.01 wt % to 5 wt % based on the total weight of the electrolyte solution, and a triphenyl phosphate-based additive in an amount ranging from 3 wt % to 7 wt % based on the total weight of the electrolyte solution.

An electrolyte includes an organic solvent, a lithium salt and additives, in particular, the additives include a fluoroethylene carbonate and a P—N bond-containing compound, the P—N bond-containing compound having a structure shown in formula I; A mass percentage of the fluoroethylene carbonate in the electrolyte is a %, a mass percentage of the P—N bond-containing compound in the electrolyte is b %, and 0.1≤a/b≤200.

Provided is a lithium secondary battery, and the lithium secondary battery of the present invention includes: a positive electrode including a first lithium-metal oxide including secondary particles formed by aggregating primary particles having a particle diameter of 2 μm or less and a second lithium-metal oxide including nickel and at least one or more metals selected from the group consisting of manganese (Mn) and cobalt (Co) and including particles having a primary particle diameter of 2 μm or more; a negative electrode; a separator interposed between the positive electrode and the negative electrode; and an electrolyte, wherein the electrolyte includes a lithium salt, a nonaqueous organic solvent, and a difluorophosphite compound containing at least one or more difluorophosphite groups.