Many electric bikes already use lithium-ion batteries. The charge and discharge of lithium-ion batteries is a chemical process in which the ions travel back and forth between the positive and negative poles beneath a calm surface. When a lithium-ion battery is charged, the lithium atoms on the positive electrode lose electrons and are oxidized to lithium ions, which enter the negative electrode through the electrolyte and gain an electron, which is then reduced to lithium atoms. When discharging, the process is reversed.
Problems such as flatulence, high temperature and explosion of lithium batteries are usually related to overcharge, overdischarge and large current, which will cause damage to the battery. When overcharge occurs, too few lithium atoms remain in the anode material, resulting in a permanent loss of battery capacity. At the negative end, when lithium atoms are saturated, recharging causes lithium metal to accumulate on the surface of the negative material, forming dendritic crystals. Over time, lithium dendrites can Pierce through the diaphragm, causing a short circuit in the anode and cathode. During overcharge, the electrolyte and other materials will often crack to produce gas, causing the battery shell or pressure valve to burst, oxygen accumulation on the surface of the negative lithium atom reaction, resulting in an explosion. Likewise, excessive discharge will also cause damage to the material.
In addition, when the current is too large, lithium ions have no time to enter the material and will gather on the surface of the material. When these lithium ions gain electrons, they will produce lithium atom crystals on the surface of the material. As lithium is the most active metal on the chemical periodic table, lithium atoms are easy to oxidize and explode with oxygen.
One of the biggest misconceptions about power batteries is that when fire related to power batteries occurs, it is always associated with the quality of the power battery.
The usage of power battery, especially the charging process, has a great influence on the power battery. Even if the quality of the power battery is in full compliance with the relevant national standards, the user can not stand the illegal operation. The fire in Beijing's Chaoyang district is a wake-up call for the habit of using power batteries. Carelessness often leads to disaster.
