The article gives you a detail analysis of battery core explosion type and help you to protect you laptop battery better. The article comes from http://www.laptop-battery-inc.co.uk/ by editor Rachel.

1. The Analysis of Battery Core Explosion Type
Battery core explosion can be summarized as three types: external short
circuit, internal short circuit and over-charge and three. Here refers
to the external of battery cell which contains it caused by internal
insulation poor design of the battery pack. When the batteries external's
occurs, electronic component has failed to cut off the circuit, the
internal batteries will generate heat, resulting in vaporization of part
of the electrolyte, the battery case stretched.
When the internal temperature of battery reach to 135 degrees, good
quality separator paper would close the pores, electrochemical reaction
is terminated or near termination of the current dips, the temperature
slowly declining, and thus avoid the explosion occurred. However, the pore
closure rate is very low, or the fine pores will not turn off the separator
paper, makes the temperature of the battery continues to rise, more
electrolyte vaporization, and finally the battery shell bursting, and
even the temperature of the battery is increased to make combustion of
materials and exploded.
The internal short-circuit is caused to puncture the diaphragm membrane
perforation burr of the copper foil and aluminum foil, or a dendrite of
lithium atoms. The acicular metal will cause the micro-short circuit.
Since the needle is very thin with a certain resistance value, therefore,
the current will not be necessarily great. The copper foil glitch in the
production process can be observed that the battery drain too fast, most
of them can be screened from batteries factory or assembly plant program.
Moreover, due to the small glitch can be burned out, so that the battery
has returned to normal. Therefore, due to glitch micro-short circuit
caused the explosion probability is not high.
The laptop batteries inside the factory are often charged shortly after
the voltage on the low side battery, but rarely an explosion occurred.
Therefore, the internal short circuit caused the explosion, mainly
because of overcharging, overcharge rear pole piece everywhere
needle-like crystalline lithium metal piercing point everywhere,
everywhere in the micro-short circuit occurs. Therefore, the battery
temperature gradually increased to a high temperature and finally the
electrolyte is gasification. This case, either the temperature is too high,
or the shell bursting air into the lithium metal the intense oxidation
reaction, is explosive ending. But overcharge lead to an internal short
circuit caused such an explosion does not necessarily occur at the time
of charging. Battery temperature has not been high enough to combust the
material, the gas is not enough to burst battery shell, consumers will

2. terminate the charge. In this case the heat generated by a large number
of micro-short circuit, slowly increased the temperature of the battery,
then the explosion occurs after a period of time.
In summary of the types of explosion, we can focus explosion-proof on the
prevention of overcharge, prevention of external short circuit and
improvement of batteries security. Prevention of overcharge and external
short circuit belongs to the electronic protection, relate to battery
system design and battery assembly. Power core security enhancements
focus on chemical and mechanical protection, relate to battery cell
manufacturer.