This invention provides nonaqueous electrolyte solutions for lithium batteries which contain one or more brominated flame retardants. The nonaqueous electrolyte solutions comprise a) a liquid electrolyte medium; b) a lithium-containing salt; and c) at least one brominated flame retardant. The brominated flame retardant is present in the electrolyte solution in a flame retardant amount.

The present invention discloses a flame-retardant and explosion-proof battery pack for an electric vehicle and a manufacturing method thereof, the battery pack comprising: at least one battery brick consisting of batteries, which are electrically connected to define a positive electrode welding sheet and a negative electrode welding sheet; a battery brick positive electrode conducting wire and a battery brick negative electrode conducting wire, which are electrically connected to the positive electrode welding sheet and the negative electrode welding sheet, respectively; and a cover and a battery of brick container, which define a first storage space that is sufficient to accommodate the batteries, wherein the first storage space is filled with a flame-retardant oil so that the batteries are immersed in the flame-retardant oil, and the positive electrode conducting wire and the negative electrode conducting wire are exposed outside the first storage space to form a battery brick assembly.

An electrolyte solution includes an electrolyte salt and an organic solvent, wherein the electrolyte salt includes lithium bis(fluorosulfonyl)imide (LiFSI), and the percentage mass content of the lithium bis(fluorosulfonyl)imide (LiFSI) in the electrolyte solution is 4.5%-11%; the organic solvent includes ethylene carbonate, and the percentage mass contents of the ethylene carbonate and the lithium bis(fluorosulfonyl)imide satisfy: 0.9≤W.sub.LiFSI/(16.77%−W.sub.EC)≤2.9. The electrolyte solution of the present disclosure can make the battery take lower cell internal resistance, excellent high temperature storage performance and high temperature cycling performance into account at the same time.

An electrochemical cell and a method of preparing the electrochemical cell are provided. The electrochemical cell, such as a lithium battery or a solid-state lithium ion battery, includes a first electrode having a solid polymer electrolyte deposited thereon, wherein the solid polymer electrolyte comprises a microporous polymer swollen with an organic carbonate liquid and a dissociable lithium salt, and a second electrode. The method of preparing an electrochemical cell includes providing the first electrode, immersing the first electrode in an electrolyte solution, depositing the solid polymer electrolyte on the immersed first electrode, and attaching the second electrode to an exposed surface of the solid polymer electrolyte, thereby forming the electrochemical cell. During operation, the solid polymer electrolyte is capable of growing a passivating polymer layer at an interface between the first electrode and the solid polymer electrolyte.

A flame-resistant composite separator for use in a lithium battery, wherein the composite separator comprises at least a first layer and a second layer laminated together, wherein: (A) the first layer comprises a layer of inorganic solid electrolyte (e.g., a sintered solid structure) or a layer of polymer composite comprising 60%-99% by volume of inorganic material particles, inorganic material fibers, and/or polymer fibers dispersed in or bonded by a first polymer; and (B) the second layer comprises a second polymer and from 0.1% to 50% by weight of a lithium salt dispersed in the second polymer; wherein the first layer and the second layer each has a thickness from 20 nm to 100 μm and a lithium-ion conductivity from 10.sup.−8 S/cm to 5×10.sup.−2 S/cm at room temperature.

An electrode assembly having a first electrode, a second electrode, and a separator therebetween, the first electrode, the second electrode, and the separator being wound in a jelly-roll shape is provided. The first electrode includes a first winding start portion, a first winding end portion, and a first coating portion having a first active material provided between the first winding start portion and the first winding end portion. The second electrode includes a second winding start portion, a second winding end portion, and a second coating portion having a second active material provided between the second winding start portion and the second winding end portion. A first electrode tab is provided at the first winding end portion of the first electrode. A first protective member is attached to a surface of the second winding end portion of the second electrode facing the first electrode tab.

A non-aqueous electrolyte solution for a lithium secondary battery and a lithium secondary battery including the same are disclosed herein. In some embodiments, a non-aqueous electrolyte solution includes a lithium salt at a concentration of 1.5 M to 2.0 M, an organic solvent containing ethylene carbonate and ethyl propionate, and a first additive represented by Formula 1, wherein the ethylene carbonate and the ethyl propionate are present in a volume ratio of 1:9 to 1.5:8.5:

NC—R—CH═CH—R.sub.1—CN   [Formula 1]

In Formula 1, R and R.sub.1 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms.

A negative electrode for a lithium metal battery, a manufacturing method thereof, and a lithium metal battery comprising the same are provided. The negative electrode includes a metal current collector, a lithium metal layer formed on at least one surface of the metal current collector, and a protective layer formed on the lithium metal layer, the protective layer comprising a metal powder or metal wire, an alloyable metal powder or alloyable metal wire, or a mixture thereof.

A secondary battery includes a positive electrode sheet which includes a positive-electrode current collector, a positive-electrode active material layer, and a coating layer arranged between the positive-electrode current collector and the positive-electrode active material layer. The coating layer includes a conductive agent and a copolymer.

A solid-state composite electrode includes active electrode particles, ionically conductive particles, and electrically conductive particles. Each of the ionically conductive particles is at least partially coated with an isolation material that inhibits inter-diffusion of the ionically conductive particles with the active electrode particles. A battery cell includes a first current collector, a solid electrolyte layer, a first solid-state composite electrode having ionically conductive particles coated with an isolation material and positioned between the first current collector and the solid electrolyte layer, a second current collector, and a second electrode positioned between the solid electrolyte layer and the second current collector. A method of forming a solid-state composite electrode includes mixing together active electrode particles and electrically conductive particles with ionically conductive particles that are each at least partially coated with an isolation material. The mixture is formed into a film via tape-casting, and sintered at a temperature greater than 600° C.