TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The positive and negative electrodes comprise flowable semi-solid or condensed liquid ion-storing redox compositions comprising gel. The flowable semi-solid or condensed liquid ion-storing redox composition has steady-state shear viscosity of 1-1000000 cP at operation temperature of redox flow energy storage device. The ion is chosen from lithium ion, sodium ion or hydrogen ion. The flowable semi-solid ion-storing redox composition comprises a solid comprising ion-storage compound, in which the ion is proton or hydroxyl ion, preferably lithium. The ion storage compound is chosen from metal fluorides such as copper fluoride, iron fluoride, iron-trifluoride, bismuth-trifluoride, cobalt-trifluoride and nickel-difluoride, and metal oxides such as cobalt oxide (CoO and Co3O4), nickel oxide, copper oxide and manganese oxide, preferably comprises an intercalation compound such as lithium-metal-phosphorus oxide compound (Li1-x-zM1-zPO4, where M is transition metal chosen from titanium, vanadium, chromium, manganese, iron, cobalt and nickel, x is 0-1 and z is positive or negative number), lithium-metal dopant-phosphorus oxide compound ((Li1-xZx)MPO4, where M is vanadium, chromium, manganese, iron, cobalt and/or nickel, Z is non-alkali metal dopant such as titanium, zirconium, niobium, aluminum or magnesium, and x is 0.005-0.05), lithium-phosphorus oxide compound (LiMPO4, where M is vanadium, chromium, manganese, iron, cobalt and nickel, and the compound is optionally doped in lithium, metal or oxygen-sites), inorganic metal compounds (Ax(M'1-aM"a)y(XD4)2, Ax(M'1-aM"a)y(D'XD'4)z, Ax(M'1-aM"a)y(X2D'7)2, (A1-aM"a)xM'y(XD'4)z, (A1-aM"a)xM'y(D'XD'4)z and (A1-aM"a)xM'y(X2D'7)z, where x, y and (l-a) are valence, A is alkali metal and/or hydrogen, M' is first-row transition metal, X is phosphorus, sulfur, arsenic, molybdenum and/or tungsten, M" is group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB and/or VIB metal, and D' is oxygen, nitrogen, carbon or halogen), ordered rocksalt compounds (LiMO2, where M is first-row transition metal, and optionally includes non-transition metal such as aluminum, calcium, magnesium and zirconium) including ( alpha )-sodium iron oxide (( alpha )-NaFeO2) and orthorhombic-lithium manganese oxide structure-type or their derivatives of different crystal symmetry. The flowable semi-solid ion-storing redox composition comprises a solid comprising amorphous carbon, disordered carbon, graphitic carbon, or metal-coated or metal-decorated carbon, a solid comprising metal, metal alloy, metalloid, metalloid alloy or silicon, a solid comprising nanostructures including nanowires, nanorods and nanotetrapods, and a solid comprising organic redox compound, preferably lithium-manganese oxide and its derivatives, layered-spinel nanocomposite, olivine (LiMPO4, where M is manganese, iron, cobalt or nickel) and their derivatives, and partially fluorinated compounds such as lithium-vanadium-phosphorus oxyfluoride (LiVPO4F). The negative electrode comprises a flowable semi-solid ion-storing redox composition comprising graphite, graphitic boron-carbon alloys, hard or disordered carbon, lithium titanate spinel, or solid metal, metal alloy, metalloid or metalloid alloy reacting with lithium to form intermetallic compounds including metals such as tin, bismuth, zinc, silver and aluminum, and metalloids such as silicon and germanium. The flowable semi-solid or condensed liquid ion-storing redox composition further comprises additive(s) such as conductive additive, thickener, and compound absorbing water. The solid is graphite, and the conductive coating material is metal, metal carbide, metal nitride or carbon. The metal is copper.    TECHNOLOGY FOCUS - POLYMERS - Preferred Membrane: The ion-permeable membrane includes polyethyleneoxide polymer sheets or Nafion (RTM: polymer membrane).