▎ 摘　　要

NOVELTY - The electrode has a film of a composite of boron nitride nanotubes (BNNTs) and at least one polymeric binder that are provided. The film of the composite intimately contacts at least one surface of the S electrode as a porous network which is selectively permeable to transport metal ions and electrolyte used in the energy storage device but impermeable to polysulfides. The BNNTs of the composite are substantially free, preferably completely free, of impurities such as hexagonal boron nitride (hBN) and/or elemental boron (B). At least a portion of the polymer binder is present in the composite as solid particulates which fix or adhere strands of BNNTs in the composite together to form the porous network. USE - Sulfur based electrode for energy storage device e.g. lithium-sulfur batteries, for metal-sulfur energy storage device and lithium-sulfur energy storage device (all claimed), used in transportation, grid storage, electric vehicles, and advanced portable electronics applications. ADVANTAGE - The electrode has high energy density, long cycle life, high efficiency, and low cost. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: an energy storage device; and an electronic device. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the sulfur based electrode for energy storage device.