A negative electrode for a lithium secondary battery, a lithium secondary battery including the negative electrode, and a method for manufacturing the lithium secondary battery, where the negative electrode includes a negative electrode current collector; and a negative electrode active material layer on at least one surface of the negative electrode current collector. The negative electrode active material layer includes a Si-containing negative electrode active material, a conductive material and a first binder polymer. The Si-containing negative electrode active material has cracks formed after activation, and a second binder polymer is present in the cracks. The first binder polymer and the second binder polymer are heterogeneous (e.g., different from each other). The lithium secondary battery shows improved life characteristics.

An electrochemical apparatus includes an electrode assembly. The electrode assembly includes a first electrode plate, a first separation layer, a second electrode plate, and a second separation layer. Along a first direction, the first separation layer includes a first protruding portion extending beyond the second electrode plate, and the second separation layer includes a second protruding portion extending beyond the second electrode plate. The first protruding portion includes a first bonding area, the second protruding portion includes a second bonding area, and adhesion between the first bonding area and the second bonding area is F1, where F1≥5 N/m. Separation layers on two sides of an electrode plate are bonded to prevent the separation layers from shrinking at high temperatures or prevent the separation layers from turning inward at edges due to impact from an electrolyte when the electrochemical apparatus falls, thereby preventing a short circuit.

An electrochemical apparatus includes an electrode assembly. The electrode assembly includes a first electrode plate, a first separation layer, a second electrode plate, and a second separation layer. Along a first direction, the first separation layer includes a first protruding portion extending beyond the second electrode plate, and the second separation layer includes a second protruding portion extending beyond the second electrode plate. The first protruding portion includes a first bonding area, the second protruding portion includes a second bonding area, and adhesion between the first bonding area and the second bonding area is F1, where F1≥5 N/m. Separation layers on two sides of an electrode plate are bonded to prevent the separation layers from shrinking at high temperatures or prevent the separation layers from turning inward at edges due to impact from an electrolyte when the electrochemical apparatus falls, thereby preventing a short circuit.

Provided are composite electrolytes having a bio-based gel electrolyte in an ordered structure of a porous solid. In some embodiments, the gel electrolyte includes a glycolate gel, a glycerate gel, a bio-based compound-derived gel or a combination thereof. Also provided are electrochemical systems (electrodeposition), redox flow batteries, fuel cells, lithium-ion batteries and lithium-metal batteries including the composite electrolytes, and methods for producing gel electrolytes. In some embodiments, the methods including reacting a polyol, optionally ethylene glycol, propanediol, butanediol, pentanediol, diethylene glycol, glycerol, or any combination thereof, with a lithium metal and/or a lithium salt, optionally lithium hydroxide, a sodium salt, optionally sodium hydroxide (NaOH), NaTFSI, NaBF.sub.4, or NaPF.sub.6; an aluminum salt; a potassium salt, a magnesium salt; a calcium salt; a zinc salt; or any combination thereof.

Provided are separators for use in an electrochemical cell comprising (a) an inorganic oxide and (b) an organic polymer, wherein the inorganic oxide comprises organic substituents. Also provided are electrochemical cells comprising such separators.

Provided are separators for use in an electrochemical cell comprising (a) an inorganic oxide and (b) an organic polymer, wherein the inorganic oxide comprises organic substituents. Also provided are electrochemical cells comprising such separators.

Novel or improved microporous single or multilayer battery separator membranes, separators, batteries including such membranes or separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries are provided. In accordance with at least certain embodiments, a multilayer dry process polyethylene/polypropylene/polyethylene microporous separator which is manufactured using the inventive process which includes machine direction stretching followed by transverse direction stretching and a subsequent calendering step as a means to reduce the thickness of the multilayer microporous membrane, to reduce the percent porosity of the multilayer microporous membrane in a controlled manner and/or to improve transverse direction tensile strength. In a very particular embodiment, the inventive process produces a thin multilayer microporous membrane that is easily coated with polymeric-ceramic coatings, has excellent mechanical strength properties due to its polypropylene layer or layers and a thermal shutdown function due to its polyethylene layer or layers. The ratio of the thickness of the polypropylene and polyethylene layers in the inventive multilayer microporous membrane can be tailored to balance mechanical strength and thermal shutdown properties.

Novel or improved microporous single or multilayer battery separator membranes, separators, batteries including such membranes or separators, methods of making such membranes, separators, and/or batteries, and/or methods of using such membranes, separators and/or batteries are provided. In accordance with at least certain embodiments, a multilayer dry process polyethylene/polypropylene/polyethylene microporous separator which is manufactured using the inventive process which includes machine direction stretching followed by transverse direction stretching and a subsequent calendering step as a means to reduce the thickness of the multilayer microporous membrane, to reduce the percent porosity of the multilayer microporous membrane in a controlled manner and/or to improve transverse direction tensile strength. In a very particular embodiment, the inventive process produces a thin multilayer microporous membrane that is easily coated with polymeric-ceramic coatings, has excellent mechanical strength properties due to its polypropylene layer or layers and a thermal shutdown function due to its polyethylene layer or layers. The ratio of the thickness of the polypropylene and polyethylene layers in the inventive multilayer microporous membrane can be tailored to balance mechanical strength and thermal shutdown properties.

A separator including a porous base and a coating layer on at least one surface of the porous base, the coating layer including (a) a carbon nanotube including an oxygen functional group and (b) a lithium ion conducting polymer, and a lithium-sulfur battery including the same. Such a separator may be capable of resolving problems caused by lithium polysulfide occurring in a lithium-sulfur battery.

A separator including a porous base and a coating layer on at least one surface of the porous base, the coating layer including (a) a carbon nanotube including an oxygen functional group and (b) a lithium ion conducting polymer, and a lithium-sulfur battery including the same. Such a separator may be capable of resolving problems caused by lithium polysulfide occurring in a lithium-sulfur battery.