Forced discharge

An experimental investigation of explosion hazards in lithium-sulfinyl chloride cells on forced discharge showed cathode limited cells are safe, but anode limited cells may explode without warning signs [1]. Extended reversal at -40°C caused explosion on warming to ambient temperature, owing to thermal runaway caused by accelerated corrosion of lithium [2], The violent explosion of a large prismatic cell of a battery is described [3], Another study of explosion mechanisms in lithium/thionyl chloride batteries is reported [4]... 

The main problem to be faced in the organization of a lithium battery waste process is to eliminate any residual lithium metal by forced discharge of the cell. Other appropriate steps would include ... 

Figure 17. 2 Schematic representation of the seasonal variations in physical forces, discharges, and suspended sediment inventory on the Amazon shelf (from Nittrouer and DeMaster 1996, and Kineke et. al. 1996). The suspended sediment inventories include the fluid mud layers, which can comprise more the 90% of the suspended material on the shelf. The timing of the 4 AmasSeds cruises are shown at the bottom of the figure. In the upper figure NBC refers to the North Brazilian Coastal Current,...

Electrical abuse tests 1. Overcharging 2. Forced discharge 3. External short circuit 4. Abnormal voltage charging 5. Abnormal current charging 6. Nail penetration (internal short)... 

A common test to determine the ability of cells to withstand voltage reversal is the forced-discharge test. The cells are deliberately discharged, at specified currents, to below 0 V by other cells in a series string or by an external power supply to determine whether a venting, rupture, or other undesired safety problem arises. 

Some cells are designed to withstand a forced discharge to specified discharge currents. The ceUs may also be designed with internal protection, such as fuses or thermal cutoff devices, to interrupt the discharge if an unsafe condition develops. 

Forced discharge (cell reversal) Voltage cutoff Use low-voltage batteries limit current drain... 

The addition of BrCl to the depolarizer may also prevent the formation of sulfur as a discharge product, at least in the early stage of the discharge, and minimize the hazards of the Li/SOa2 battery attributable to sulfur or discharge intermediates. The cells show abuse resistance when subjected to the typical tests, such as short circuit, forced discharge, and exposure to high temperatures. ... 

The construction of the spiral-wound cylindrical battery is shown in Fig. 14.78. These batteries typically have several safety devices incorporated in their design to provide protection against such abusive conditions as short circuit, charging, forced discharge, and over heating. Two safety devices are shown in the figure—a pressure relief vent and a resettable thermal switch, called a positive thermal coefficient (PTC) device. The safety relief vent is designed to release excessive internal pressure to prevent violent rupture if the battery is heated or abused electrically. 

To be robust or rugged, the system design should take into account possible forced discharge/short circuit of the fuel cell power source. Though fuel cells will not be able to source very high peak currents similar to batteries, adequate precautions must be taken to limit the current drawn from the fuel cell through... 

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