NOVELTY - An electrode (E1) comprises a lithium titanate spinel (I) of specific formulae. (I) comprises lithium metal oxide and a portion of titanium in (I) is replaced by cations selected from vanadium, chromium, neobium, molybdenum, tantalum or tungsten.    USE - As electrode for a rechargeable lithium ion electrochemical cell (claimed) or electrochemical capacitors used in consumer electronics such as camcorders, cell phones, notebook computers, digital cameras and the like, and also includes applications requiring higher power density such as electric vehicles, gas-electric hybrid vehicles, power tools, and military applications and equipment.    ADVANTAGE - The use of the lithium titanate spinels in electrodes provided high lithium ion conductance, high electron conductance, fast lithium ion intercalation rate, and increased power density (this is because the substitution of Ti4+ in the spinel, with M provides increased electronic conductivity and high lithium ion intercalation rates). The electrode involves the use of substituted lithium titanate spinels that have an isomorphous crystal lattice occupancy in comparison to Li4Ti5O12 spinel. Also the substituting ions are either aliovalent or isovalent to Ti4+ and are not in their highest oxidation state, or the substitution forces part of titanium to 3+ oxidation state; therefore, the substitution ions have free valence electrons, which enhances electron conductivity.    DETAILED DESCRIPTION - An electrode comprises a lithium titanate spinel (I) of formula Li4Ti5-xMxO12; Li4Ti5-zM1-z1M2z2M3z3 . . . MkzkO12; Li4Ti5-x-bMxB'1bO12; Li-3+aTi6-a-xMxO12; Li3+aTi6-a-x-bMxB'bO12; or Li4-cMgcTi5-xMxO12.    z=0.1 to 2.5;    z1, z2, z3 upto zk=0 to 2.5;    x=0.1 to 2.5;    a=0 to 1;    b=0 to 2.5;    c=0 to 1.5;    M=cations selected from V, Cr, Nb, Mo, Ta or W;    M1, M2, M3 upto Mk=cation selected from V, Cr, Nb, Mo, Ta or W;and    B'=cation selected from Zr, Ce, Si or Ge.    Provided that z and z1, z2, z3 upto zk satisfy the equation, where z=z1+z2+z3+ . . . zk. INDEPENDENT CLAIMS are included for the following    (1) a rechargeable lithium ion electrochemical cell comprising: a negative electrode member comprising an electrochemically active material (M1); a positive electrode member comprising a second electrochemically active material (M2); an electrolyte comprising a lithium salt allowing for lithium ion conductance between the negative electrode and the positive; a lithium-permeable separator located between the negative electrode and the positive electrode; and where at least one of the (M1) or (M2) comprises the lithium titanate electrode (E1); and    (2) a method for making a lithium titanate spinel involving contacting titanium oxide, lithium titanate spinel, and at least one species of lithium metal oxide comprising at least one cation selected from vanadium, chromium, neobium, molybdenum, tantalum or tungsten; and heating to at least 600 to 1100 degrees C under an atmosphere comprising hydrogen (0.1 to 50) and at least one selected from the group of nitrogen and noble gases, or comprising carbon monoxide (1 to 70%) and at least one selected from carbon dioxide, nitrogen or noble gases.