High performance flexible lithium-sulfur flexible energy storage devices include a flexible lithium metal anode for an energy storage device comprising an electrically conducting fabric functionalised with a 3D hierarchical MnO.sub.2 nanosheet lithiophilic material; a flexible graphene/sulfur cathode protected by a FBN/G interlayer; and a flexible separator for an energy storage device, wherein the separator comprises one or more microporous films of Li ion selective permeable polyolefin material wherein at least a portion of the pores of the film are associated with nanoporous polysulfone polymer positioned between the anode and the cathode.

Battery separators and methods of making such separators are provided. The separators can be used in various alkaline batteries such as a Zn/MnO.sub.2 battery or the like. An alkaline battery separator comprises a first layer of polyvinyl alcohol fibers, a second layer of cellulose or a cellulose derivative and a third layer comprising a water soluble polymer. The battery separator has reduced pore sizes to reduce clogging, while still maintaining desirable wet ionic resistance, basis weight and absorption performance.

Battery separators and methods of making such separators are provided. The separators can be used in various alkaline batteries such as a Zn/MnO.sub.2 battery or the like. An alkaline battery separator comprises a first layer of polyvinyl alcohol fibers, a second layer of cellulose or a cellulose derivative and a third layer comprising a water soluble polymer. The battery separator has reduced pore sizes to reduce clogging, while still maintaining desirable wet ionic resistance, basis weight and absorption performance.

Disclosed are a micropore-filled amphoteric membrane for low vanadium ion permeability, a method of manufacturing the same, and a vanadium redox flow battery including the amphoteric membrane. The micropore-filled amphoteric membrane for low vanadium ion permeability minimizes crossover of vanadium ions, which occurs between a catholyte and an anolyte in a redox flow battery, and has low membrane resistance and thus has remarkably improved performance as compared to commercially available ion-exchange membranes such as Nafion, and accordingly, can be effectively used in the manufacture of a redox flow battery. In addition, the micropore-filled amphoteric membrane is continuously manufactured through a roll-to-roll process, and thus the manufacturing process is simple and manufacturing costs can be greatly reduced.

Disclosed are a micropore-filled amphoteric membrane for low vanadium ion permeability, a method of manufacturing the same, and a vanadium redox flow battery including the amphoteric membrane. The micropore-filled amphoteric membrane for low vanadium ion permeability minimizes crossover of vanadium ions, which occurs between a catholyte and an anolyte in a redox flow battery, and has low membrane resistance and thus has remarkably improved performance as compared to commercially available ion-exchange membranes such as Nafion, and accordingly, can be effectively used in the manufacture of a redox flow battery. In addition, the micropore-filled amphoteric membrane is continuously manufactured through a roll-to-roll process, and thus the manufacturing process is simple and manufacturing costs can be greatly reduced.

Provided are electrochemical cells including separators permeable to some materials and impermeable to other materials in electrolytes. Also provide are methods of forming such separators. The selective permeability of a separator is achieved by its specific pore diameter and a narrow distribution of this diameter. Specifically, a species responsible for ion transport in an electrochemical cell are allowed to pass through the separator, while another species is blocked thereby preventing degradation of the cell. For example, a species containing lithium ions is allowed to pass in rechargeable cells, while one or more species containing transition metals are blocked. In some embodiments, a separator may include a membrane layer with at least 90% of pores of this having a diameter of between about 0.1 nanometers and 1.0 nanometer. The membrane layer may be a standalone layer or supported by a membrane support.

Provided are electrochemical cells including separators permeable to some materials and impermeable to other materials in electrolytes. Also provide are methods of forming such separators. The selective permeability of a separator is achieved by its specific pore diameter and a narrow distribution of this diameter. Specifically, a species responsible for ion transport in an electrochemical cell are allowed to pass through the separator, while another species is blocked thereby preventing degradation of the cell. For example, a species containing lithium ions is allowed to pass in rechargeable cells, while one or more species containing transition metals are blocked. In some embodiments, a separator may include a membrane layer with at least 90% of pores of this having a diameter of between about 0.1 nanometers and 1.0 nanometer. The membrane layer may be a standalone layer or supported by a membrane support.

Battery separators, and lead-acid batteries comprising battery separators, are generally provided. In some embodiments, the battery separators described herein have one or more features that enhance their suitability for various applications (e.g., lead-acid battery applications). In one embodiment, a battery separator described herein comprises at least two phases. In some cases, each phase may have a one or more features that result in a battery separator having enhanced physical properties. For example, the dual-phase battery separator may exhibit reduced electrical and ionic resistance, enhanced acid filling capacity, reduced acid stratification, and enhanced thermal and oxidative stability compared to conventional battery separators.

Disclosed is an all-solid-state lithium ion secondary battery excellent in cycle characteristics. The battery may be an all-solid-state lithium ion secondary battery, wherein an anode comprises anode active material particles, an electroconductive material and a solid electrolyte; wherein the anode active material particles comprise at least one active material selected from the group consisting of elemental silicon and SiO; and wherein a BET specific surface area of the anode active material particles is 1.9 m.sup.2/g or more and 14.2 m.sup.2/g or less.

A secondary battery for cycling between a charged and a discharged state, wherein a 2D map of the median vertical position of the first opposing vertical end surface of the electrode active material in the X-Z plane, along the length LE of the electrode active material layer, traces a first vertical end surface plot, EVP1, a 2D map of the median vertical position of the first opposing vertical end surface of the counter-electrode active material layer in the X-Z plane, along the length LC of the counter-electrode active material layer, traces a first vertical end surface plot, CEVP1, wherein for at least 60% of the length Lc of the first counter-electrode active material layer (i) the absolute value of a separation distance, SZ1, between the plots EVP1 and CEVP1 measured in the vertical direction is 1000 μm≥|SZ1|≥5 μm.