A battery cell assembly , comprising: a plurality of cylindrical cell blocks , each including a plurality of cylindrical cells ; a block cover configured to cover an upper side of the plurality of cylindrical cell blocks and electrically connect the plurality of cylindrical cell blocks ; a cooling plate located opposite to the block cover and disposed at a lower side of the plurality of cylindrical cell blocks ; and a heat transfer member disposed between the cooling plate and the plurality of cylindrical cell blocks and having a plurality of thermal interface materials corresponding to bottom portions of the plurality of cylindrical cells , wherein the outer surfaces of the plurality of cylindrical cell blocks have a shape corresponding to the outer surface of a facing neighboring cylindrical cell block such that neighboring cell blocks are coupled with each other in a block type characterized in that each of the plurality of cylindrical cell blocks includes: the plurality of cylindrical cells ; a bottom cover configured to accommodate the bottom portions of the plurality of cylindrical cells ; a top cover coupled to the bottom cover and configured to cover top portions of the plurality of cylindrical cells ; a pair of bus bar members provided at an upper side of the top cover to electrically connect the plurality of cylindrical cells ; and an insulation member provided between the pair of bus bar members . a plurality of cylindrical cell blocks , each including a plurality of cylindrical cells ; a block cover configured to cover an upper side of the plurality of cylindrical cell blocks and electrically connect the plurality of cylindrical cell blocks ; a cooling plate located opposite to the block cover and disposed at a lower side of the plurality of cylindrical cell blocks ; and a heat transfer member disposed between the cooling plate and the plurality of cylindrical cell blocks and having a plurality of thermal interface materials corresponding to bottom portions of the plurality of cylindrical cells , wherein the outer surfaces of the plurality of cylindrical cell blocks have a shape corresponding to the outer surface of a facing neighboring cylindrical cell block such that neighboring cell blocks are coupled with each other in a block type characterized in that each of the plurality of cylindrical cell blocks includes: the plurality of cylindrical cells ; a bottom cover configured to accommodate the bottom portions of the plurality of cylindrical cells ; a top cover coupled to the bottom cover and configured to cover top portions of the plurality of cylindrical cells ; a pair of bus bar members provided at an upper side of the top cover to electrically connect the plurality of cylindrical cells ; and an insulation member provided between the pair of bus bar members . the plurality of cylindrical cells ; a bottom cover configured to accommodate the bottom portions of the plurality of cylindrical cells ; a top cover coupled to the bottom cover and configured to cover top portions of the plurality of cylindrical cells ; a pair of bus bar members provided at an upper side of the top cover to electrically connect the plurality of cylindrical cells ; and an insulation member provided between the pair of bus bar members . <EOS>