After months of silence following a global recall of its Galaxy Note 7 smartphone last October, Samsung disclosed its lengthy findings as to what caused the device’s batteries to overheat and catch fire. Based on the company’s own investigation and independent scientific analysis of the issues by three consulting bodies, the overheating was caused by separate problems in batteries sourced from two different suppliers. In the case of batteries sourced from A (Samsung SDI ), there wasn’t enough room between the heat-sealed protective pouch around the battery and its internals . In the worst scenarios, that caused electrodes inside each battery to crimp, weaken the separator between the electrodes, and cause short circuiting . In the case of batteries sourced from B (Amperex Technology Limited), some cells were missing insulation tape, and some batteries had sharp protrusions inside the cell that led to damage to the separator between the anode and catho...