ELECTROLYTE SPILLAGE AND ELECTRIC SHOCK
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erates the reactions between the negative electrodes and the battery electrolyte. Select abuse-tolerant materials and protecting cells within the battery against overcharge and overdischarge to mitigate the hazards of exposing battery materials to high temperatures. Overcharge and overdischarge protection may be achieved through adjusting the battery cell chemistry to minimize the effects of overcharge and overdischarge using protective battery electronics. In addition, the battery cell chemistry may be adjusted to protect the electrolyte from cell oxidation during battery overcharge. By introducing an electrolyte additive, the reaction will reversibly oxidize above the normal maximum positive electrode potential and below the potential at which the bulk electrolyte material oxidizes. Overcharge and overdischarge protection may be improved by ensuring that each cell contains a chemically balanced amount of positive and negative electrode materials. Battery protection electronics also provide cell protection against battery overcharge and overdischarge by using a combination of battery pack fuses and internal safety mechanisms. Using smart battery protection, the electrical safety mechanism operates during accidental overcharge, when gas evolves. Although normal cell reactions do not generate excessive amounts of gas, pressure build-up causes venting due to gas formation. This in turn leads to failure of the traction battery due to loss of electrolyte. The mechanism operates upon raising internal cell pressure until a vent opens. This in turn breaks the battery circuit. In a battery pack, an individual battery using an organic electrolyte may cause hazardous electrolyte spills in the event the cells are damaged. The design of the cell and battery container requires seals that can prevent electrolyte spills. Optimizing the amount of battery electrolyte can limit the severity of spills that occur in addition to battery seals. The amount of electrolyte required to conduct ions throughout the life of the cell must also account for the electrolyte decomposition during cycling.
BATTERY PACK SAFETY—ELECTROLYTE SPILLAGE AND ELECTRIC SHOCK The EVs currently produced worldwide carry a large number of traction batteries onboard. Therefore, a large amount of electrolyte is in either liquid or gel form. In the event of an EV accident, a rollover or crash, there is an associated hazard associated with exposure to such a large amount of electrolyte. This hazard further extends to vehicle occupants,
