NOVELTY - The lithium ion hybrid battery pack (100) comprises a battery module (200) comprising cells (110), and a spacer. The battery module surrounds a case member. The spacer is mounted between cells. The spacer has a frame structure, and is in lattice form in an outer periphery of the cell. An output of the battery cell (A) is greater than an output of the battery cell (B) of 30-200%. The capacity of the battery cell (B) is bigger than the capacity of the battery cell (A). The battery pack further includes a cathode active material in which the crystalline structure is stable.    USE - The lithium ion hybrid battery pack is useful in an energy storage device including an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, a system for power storage and a smart grid (all claimed).    ADVANTAGE - The safe lithium ion hybrid battery pack has high-capacity, excellent weather-resistance, prolonged service life and less weight, and is cost-effective and eco-friendly.    DETAILED DESCRIPTION - The lithium ion hybrid battery pack (100) comprises a battery module (200) comprising cells (110), and a spacer. The battery module surrounds a case member. The spacer is mounted between cells. The spacer has a frame structure, and is in lattice form in an outer periphery of the cell. An output of the battery cell (A) is greater than an output of the battery cell (B) of 30-200%. The capacity of the battery cell (B) is bigger than the capacity of the battery cell (A). The battery pack further includes a cathode active material in which the crystalline structure is stable and for showing the sudden inclination during charging/discharging in the discharge profile, and a battery module block. The battery modules are different from the output and capacity. The battery modules are serially connected. The battery cell within the battery modules is connected in parallel. INORGANIC CHEMISTRY - Preferred Components: The cathode active material includes lithium oxide, and has olivine structure of formula (Li1+aFe1-xMx(PO4-b)Xb) (I). The battery pack further comprises lithium transition-metal oxides of formula (Li1+cMe1-yM1yOz) (II).    M = Al, Mg, Ni, Co, Mn, Ti, Ga, Cu, V, Nb, Zr, Ce, In, Zn or Y;    X = F, S, or N;    a, c = -0.5 to +0.5;    b = 0-0.1;    Me = transition metal;    M1 = Al, Mg, Ti, Ga, Cu, V, Nb, Zr, Ce, In, Zn or Y;    y = 0-0.5; and    z = 2-4.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a battery pack.    Battery pack (100)    Cells (110)    Storage device (140)    Module. (200)