An electrochemical cell that cycles lithium ions is provided. The electrochemical cell includes a first electrode, a second electrode, and an electrolyte layer disposed between the first electrode and the second electrode. The first electrode includes a first plurality of solid-state electroactive material particles and a first polymeric gel electrolyte, where the first polymeric gel electrolyte includes a first additive. The second electrode includes a second plurality of solid-state electroactive material particles and a second polymeric gel electrolyte that is different from the first polymeric gel electrolyte, where the second polymeric gel electrolyte includes a second additive. The electrolyte layers include a third polymeric gel electrolyte that is different from both the first polymeric gel electrolyte and the second polymeric gel electrolyte.

An electrochemical cell that cycles lithium ions is provided. The electrochemical cell includes a first electrode, a second electrode, and an electrolyte layer disposed between the first electrode and the second electrode. The first electrode includes a first plurality of solid-state electroactive material particles and a first polymeric gel electrolyte, where the first polymeric gel electrolyte includes a first additive. The second electrode includes a second plurality of solid-state electroactive material particles and a second polymeric gel electrolyte that is different from the first polymeric gel electrolyte, where the second polymeric gel electrolyte includes a second additive. The electrolyte layers include a third polymeric gel electrolyte that is different from both the first polymeric gel electrolyte and the second polymeric gel electrolyte.

There is disclosed a method of making a surface-modified alkali metal material for electrochemical use, the method comprising bringing a barrier agent into frictional contact with an alkali metal substrate to form a tribochemical barrier layer on the substrate. Also disclosed is a surface-modified alkali metal material for electrochemical use, the material comprising an alkali metal substrate bearing a tribochemical barrier layer.

An electrode for a lithium battery contains a metal layer coated with a coating layer containing an organic binder and a metal compound. The metal compound is selected from aluminium oxide, silicon dioxide, zirconium oxide, mixed oxides including zirconium, mixed oxides including aluminium, lithium zirconium phosphate, and mixtures thereof. The metal compound is made of aggregates of primary particles with a number mean primary particle size d.sub.50 of 5 nm-100 nm, obtained by a pyrogenic process. The weight ratio of the metal compound to the organic binder in the coating layer is from 0.1 to 10.

An electrode for a lithium battery contains a metal layer coated with a coating layer containing an organic binder and a metal compound. The metal compound is selected from aluminium oxide, silicon dioxide, zirconium oxide, mixed oxides including zirconium, mixed oxides including aluminium, lithium zirconium phosphate, and mixtures thereof. The metal compound is made of aggregates of primary particles with a number mean primary particle size d.sub.50 of 5 nm-100 nm, obtained by a pyrogenic process. The weight ratio of the metal compound to the organic binder in the coating layer is from 0.1 to 10.

A lithium-replenishing additive is provided. The lithium-replenishing additive includes a lithium-rich-material core and a shell layer disposed at the lithium-rich-material core. The lithium-rich-material core is made of a lithium-rich material with an average chemical formula of aNi.sub.xM.sub.yO.sub.2 .Math.bLi.sub.2O, where 0.95≤x≤1, 0.01≤y≤0.05, 1≤z≤1.15, 0.8≤a≤1.1, 0.8≤b≤1.1, and the M includes one or more of copper (Cu), cobalt (Co), aluminum (Al), titanium (Ti), vanadium (V), zirconium (Zr), or iron (Fe). The shell layer includes a polymer layer. A preparing method of a lithium-replenishing additive and a lithium secondary battery are further provided.

A lithium-replenishing additive is provided. The lithium-replenishing additive includes a lithium-rich-material core and a shell layer disposed at the lithium-rich-material core. The lithium-rich-material core is made of a lithium-rich material with an average chemical formula of aNi.sub.xM.sub.yO.sub.2 .Math.bLi.sub.2O, where 0.95≤x≤1, 0.01≤y≤0.05, 1≤z≤1.15, 0.8≤a≤1.1, 0.8≤b≤1.1, and the M includes one or more of copper (Cu), cobalt (Co), aluminum (Al), titanium (Ti), vanadium (V), zirconium (Zr), or iron (Fe). The shell layer includes a polymer layer. A preparing method of a lithium-replenishing additive and a lithium secondary battery are further provided.

A negative electrode material includes a silicon-based material, where a particle of the silicon-based material includes at least one recessed portion, and the recessed portion is 50 nm to 20 μm in width, and 50 nm to 10 μm in depth. The recessed structure leaves room for the silicon-based material to swell, thereby solving the problem of large volume swelling of the silicon-based material. In addition, when the silicon-based material with the recessed structure is composited with a carbon material, a conductive agent, and the like to form a negative electrode plate, small particles of the carbon material and the conductive agent are embedded into the recessed portion of the silicon-based material, solving the problem of low compacted density of the silicon-based negative electrode material with a recessed structure, and compensating for the low volumetric energy density of the recessed structure.

Component A: a carboxymethyl cellulose having a degree of carboxymethyl substitution per anhydroglucose unit of 0.45 or more or a salt thereof and Component B: a saturated carboxylic acid having 6 or less carbon atoms or a salt thereof are contained.

This separator for a nonaqueous electrolyte secondary battery comprises a porous substrate, a heat-resistant layer that is formed on the porous substrate, and clusters of filler particles that are present in dot shapes on the surface of the heat-resistant layer. The filler particles are particles of a compound including at least one of phosphorus, silicon, boron, nitrogen, potassium, sodium, and bromine, and the transformation point at which the filler particles transform from a solid phase to a liquid phase or thermally decompose is in the range 180° C.-1000° C. This separator electrode for a nonaqueous electrolyte secondary battery can suppress heat production of the battery during a nail puncture test, while also suppressing an increase in battery resistance.