The charging pile is actually equivalent to a gas dispenser in a gas station. The popularization of new energy vehicles has allowed charging piles to gradually enter people's lives. According to people's actual situation, new energy vehicle owners use fast charging, slow charging and flying leads as their main charging methods. First of all, flying wire is the most dangerous charging method that is highly discouraged, and slow charging takes a long time, especially for car owners who don’t have private charging stations. The slow charging method puts too much pressure on time, energy and money, and fast charging car battery has Rumors of damaging the battery have been circulating in the world to be charged in a combination of fast and slow charging.

With the accumulation of fast charging car battery users, basic charging problems are gradually exposed. There is no interoperability between charging equipment and enterprises. Car owners must not only grasp the location of the charging pile, but also understand the brand and payment method of the charging pile.

To discuss the impact of DC charging on the battery, we must first understand the fast charging car battery.

At present, most fast charging car batteries on the market are lithium-ion batteries, which have two poles: the positive electrode is a lithium compound, and the negative electrode is graphite.

During charging, lithium ions (Li+) are generated on the positive electrode of the battery, and the generated lithium ions (Li+) move from the positive electrode to the negative electrode through the electrolyte. The graphite of the negative electrode has a microporous layered structure and reaches the lithium ion of the negative electrode. (Li+) embedded in the micropores of the carbon layer, the more lithium ions (Li+) inserted, the higher the charge capacity; during discharge (that is, the process when we use the battery), the lithium ions (Li+) embedded in the carbon layer of the negative electrode ) Escapes and moves back to the positive electrode. The more lithium ions (Li+) that return to the positive electrode, the higher the discharge capacity. What we usually call battery capacity refers to the discharge capacity. Therefore, in an ideal state, during the charging and discharging process of a lithium battery, it is actually the movement state of lithium ions (Li+) from the positive electrode → the negative electrode → the positive electrode. As long as the chemical structure of the positive and negative materials basically does not change, the reversibility of the battery charge and discharge Very well, lithium ion (Li+) batteries can guarantee long-term cycling.

The fast charging car battery is mainly to ensure that lithium ions (Li+) are quickly inserted from the positive electrode and quickly inserted into the negative electrode, without causing the deposition of lithium ions (Li+). However, when the current increases, a semi-permeable membrane (SEI membrane) on the surface of the negative electrode (graphite) of the electrode will rupture to a certain extent, causing the electrode material and the electrolyte to react with each other. In addition, the temperature increase will be accompanied by some side reactions, such as the decomposition of the electrolyte and the formation of deposits on the electrodes, which will reduce the reversibility and the battery capacity will gradually decrease.