Electric vehicle battery plate vulcanizing crystalline state
Electric vehicle battery plate is an important supply electricity source, after hundreds of times cycle, plate will produce sulfide phenomenon, in the process of discharging lead sulfate, which is formed by the original is a tiny particles, called one-time crystals, once the charging can disappear.
Under special circumstances, the electric vehicle battery plate surface will form a hard layer of lead sulfate white coarse grain layer.
It's hard to dissolve lead sulfate crystallization, and cannot be converted to lead dioxide during normal charging and spongy lead, this phenomenon is known as the 'lead sulfate hardening', 'cure' for short.
Electric vehicle battery after the plate, because of the compact crystalline structure, poor electrical conductivity, large volume, seriously blocked the plate active substances of tiny pore, hindered the penetration and diffusion of the electrolyte, reduce to participate in the reaction of active substances, battery capacity decline, internal resistance increases, can not supply large starting current, cure serious when battery will not be able to continue to use.
Electric vehicle battery after each discharge, the positive and negative plates of different active substances are transformed into lead sulfate, revert to different active substances after charging.
Often over discharge, small current discharge, low temperature, large current discharge, supplementary electricity is not timely, charging is not high enough, acid density, inside the battery, the long-stalled water shortage, lead sulfate accumulation on the surface of the plate and excessive dissolved in the electrolyte, the saturated state.
The lead sulfate particles under the fluctuations in temperature, acid concentration, crystallization precipitation in the plate surface again.
Since the polycrystal tend to reduce the surface free energy as a result, after the reorganization of crystal showed a trend of increase, thickening.
Because the lead sulfate is the undissolved electrolyte, crystals after restructuring its specific surface area decreases, and the solubility and dissolution rate in the electrolyte is reduced.
Lead sulfate attached in the plate surface and micropore hindered the normal diffusion of batteries, and lead sulfate conductance adverse resistance is big, the battery in the normal charge in ohm polarization, concentration polarization increases, charge acceptance rate is reduced, the active substance is not yet fully in translation has reached water decomposition, polarization voltage battery heated up fast charging cannot continue, in turn, active substances into incomplete, therefore become the capacity to reduce and shorten the life of reason.