NOVELTY - The rechargeable lithium battery module (410) comprises a first rechargeable lithium battery cell combined with a second rechargeable lithium battery cell. The first rechargeable lithium battery cell comprises a positive electrode including a first positive active material and a negative electrode including a first negative active material. The second rechargeable lithium battery cell comprises the positive electrode including the first positive active material or a second positive active material or the negative electrode comprising a second negative active material.    USE - The rechargeable lithium battery module is useful for an integrated starter and generator (claimed) that is useful in automobiles.    ADVANTAGE - The rechargeable lithium battery module has small volume, improved low-temperature discharge characteristics, rapid charge characteristics and improved cycle-life characteristics.    DETAILED DESCRIPTION - The rechargeable lithium battery module (410) comprises a first rechargeable lithium battery cell combined with a second rechargeable lithium battery cell. The first rechargeable lithium battery cell comprises a positive electrode including a first positive active material and a negative electrode including a first negative active material. The second rechargeable lithium battery cell comprises the positive electrode including the first positive active material or a second positive active material or the negative electrode comprising a second negative active material. The second positive active material is different from the first positive active material. The second negative active material is different from the first negative active material. The rechargeable lithium battery module has an output voltage of 13.6-15.6 V. The first positive active material and the second positive active material have a structure of a layered structure, a spinel-based structure and an olivine-based structure. The first negative active material and the second negative active material comprise a carbon-based material consisting of a crystalline carbon-based material and an amorphous carbon-based material. The rechargeable lithium battery module further comprises four rechargeable lithium battery cells connected in series to form a main rechargeable battery, a diode electrically connected to an end of the main rechargeable battery, and a resistor electrically connected with an auxiliary rechargeable battery in series. The auxiliary rechargeable battery comprises a rechargeable lithium battery cell connected to the main rechargeable battery in parallel, and has the rechargeable lithium battery cells.    DESCRIPTION OF DRAWING(S) - The diagram shows a block diagram of a rechargeable lithium battery module.    Integrated starter and generator (30)    Rechargeable lithium battery cell (41)    Rechargeable battery module. (410)