An electrochemical cell stack , comprising: a first electrochemical cell including a first current collector having a first surface and a second surface, the first surface of the first current collector having a semi-solid cathode disposed thereon, and the second surface of the first current collector being uncoated; the first electrochemical cell further including a second current collector having a first surface and a second surface, the first surface of the second current collector having a semi-solid anode dispersed thereon and the second surface of the second current collector being uncoated; a second electrochemical cell including a third current collector having a first surface and a second surface, the first surface of the third current collector having a semi-solid cathode disposed thereon, the second surface of the third current collector being uncoated; the second electrochemical cell further including a fourth current collector having a first surface and a second surface, the first surface of the fourth current collector having a semi-solid anode dispersed thereon and the second surface of the fourth current collector being uncoated; a third electrochemical cell including a fifth current collector having a first surface and a second surface, the first surface of the fifth current collector having a semi-solid cathode disposed thereon and the second surface of the fifth current collector being uncoated; the second surface of the first current collector coupled to the second surface of the fifth current collector via a first spacer; the second surface of the second current collector coupled to the second surface of the fourth current collector via a second spacer; a first separator disposed between the semi-solid anode of the second current collector and the semi-solid cathode of the first current collector ; a second separator disposed between the semi-solid anode of the fourth current collector and the semi-solid cathode of the third current collector . a first electrochemical cell including a first current collector having a first surface and a second surface, the first surface of the first current collector having a semi-solid cathode disposed thereon, and the second surface of the first current collector being uncoated; the first electrochemical cell further including a second current collector having a first surface and a second surface, the first surface of the second current collector having a semi-solid anode dispersed thereon and the second surface of the second current collector being uncoated; a second electrochemical cell including a third current collector having a first surface and a second surface, the first surface of the third current collector having a semi-solid cathode disposed thereon, the second surface of the third current collector being uncoated; the second electrochemical cell further including a fourth current collector having a first surface and a second surface, the first surface of the fourth current collector having a semi-solid anode dispersed thereon and the second surface of the fourth current collector being uncoated; a third electrochemical cell including a fifth current collector having a first surface and a second surface, the first surface of the fifth current collector having a semi-solid cathode disposed thereon and the second surface of the fifth current collector being uncoated; the second surface of the first current collector coupled to the second surface of the fifth current collector via a first spacer; the second surface of the second current collector coupled to the second surface of the fourth current collector via a second spacer; a first separator disposed between the semi-solid anode of the second current collector and the semi-solid cathode of the first current collector ; a second separator disposed between the semi-solid anode of the fourth current collector and the semi-solid cathode of the third current collector . <EOS>