Take you to know the real lead carbon battery

A lead-carbon battery is a capacitive lead-acid battery in which activated carbon is added to the negative electrode of a lead-acid battery. The positive active material of the common lead-acid battery is a lead oxide (PbO2), and the negative active material is lead (Pb). If the negative active material Pb is replaced by activated carbon, the ordinary lead-acid battery becomes a hybrid capacitor; if the activated carbon is mixed In the negative electrode active material Pb, a common lead-acid battery becomes a lead-carbon battery. It combines a carbon material (C) having a double layer capacitance characteristic with a sponge lead (Pb) negative electrode to form a Lead-carbon dual function composite electrode (hereinafter referred to as a Lead-carbon electrode) having both a capacitance characteristic and a battery characteristic. The Lead-carbon composite electrode is then assembled with the PbO2 positive electrode to form a Lead-carbon battery.

Lead-carbon battery is a new type of super battery. You can understand that lead-carbon battery combines lead-acid battery and super-capacitor: it not only takes advantage of the ultra-capacitor instant large-capacity charging but also plays a lead-acid battery. It has a superior energy advantage and has very good charge and discharge performance - it can be fully charged in 90 minutes (if the lead-acid battery is charged and discharged, the life is less than 30 times). Moreover, due to the addition of carbon (graphene), the sulphation of the negative electrode is prevented, which improves a factor of battery failure in the past and prolongs battery life.

Job characteristics

1) When the battery is charged and discharged in a frequent instantaneous high current, the carbon material is mainly discharged or received by the carbon material, and the "negative sulfation" of the lead-acid battery is suppressed, thereby effectively prolonging the service life of the battery;

2) When the battery is in a long time of low current operation, it is mainly operated by a sponge lead anode to continuously provide energy;

3) The high carbon content of the Lead-carbon super composite electrode enables the electrode to have better low-temperature start-up capability, charge acceptance capability and high current charge and discharge performance than conventional lead-acid batteries.

Performance characteristics

In terms of performance, lead-carbon batteries are characterized by both lead-acid batteries and capacitors. The addition of activated carbon increases the power density of the battery and prolongs the cycle life. At the same time, since the activated carbon occupies part of the electrode space, the energy density is lowered, and the amount of gas evolution of the electrode may also be increased. In terms of process, the addition of activated carbon increases the difficulty of slurrying and pole coating. In general, lead-carbon battery performance is superior to ordinary lead-acid batteries, is an advanced lead-acid battery, and is also the mainstream direction of lead-acid battery technology development.

There is a problem with the development situation

1) The carbon material of the high-carbon lead-acid battery is added in an amount of 4% or more. For an ordinary lead-acid battery, the amount of the carbon material added is 0.2% or less. So the best addition to the carbon material of lead-carbon batteries is a problem to be explored.

2) The mixing of lead powder and carbon material, in which way, the carbon material and the lead powder can be uniformly mixed, and the stability of the negative lead-carbon mixed material paste can be ensured, and the bonding ability of the electrode plate and the lead paste can be achieved. Ensure the strength requirements of the negative plate.

3) After the externalization, the surface of the negative electrode plate is precipitated with carbon material, and the grid expansion deformation phenomenon occurs.

4) The addition of carbon material will aggravate the hydrogen evolution of the negative electrode, causing the battery to lose water seriously, and the maintenance performance is not reduced, resulting in a change in the battery failure mode.

5) The density difference between the carbon material and the lead powder is very large, and the porosity of the negative electrode plate is greatly increased after the addition, and the negative electrode is easily oxidized.

 solution

1) If the lead-carbon battery has the effect of the supercapacitor, the amount of carbon material added must be greater than 4%. Domestic and foreign studies have shown that the amount of carbon material can be increased by 10% to 20%.

2) If the stability of the negative lead-carbon mixed material paste and the bonding ability of the electrode plate and the lead paste are ensured, a binder suitable for a lead-acid battery, such as PTFE, CMC, neoprene or the like, must be added.

3) To ensure the strength of the negative plate, first ensure the wet density of the paste when the paste is used, and the wet density of the paste is best at 4.2~4.5g/cm3. Adding the proper amount of binder or short fiber, and using machine paste to increase the pressure of the paste can achieve the purpose of ensuring the strength of the plate.

4) In order to prevent the loss of carbon material and the expansion deformation of the grid during the formation, an internalization process can be adopted, and the internal current design process should be appropriately adjusted.

5) For the problem of hydrogen evolution of the negative electrode, an appropriate amount of a hydrogen sulfide-suppressing additive such as a compound of silver oxide or zinc may be added to the negative electrode active material.

6) In the prevention of oxidation of the negative electrode, an internalization process can be adopted: if it is externalized, the anaerobic drying time should be appropriately extended.

Prospects

Lead-carbon battery is the most advanced technology in the field of lead-acid batteries and is also the development focus of the international new energy storage industry. It has a very broad application prospect. Energy storage battery technology is one of the key technologies that restrict the development of new energy storage energy industry. The energy storage fields of photovoltaic power storage, wind power storage, and power grid peaking require batteries to have high power density, long cycle life, and low price. Lead-carbon batteries, lithium-ion batteries, and flow batteries are the three major development directions of new energy storage batteries. Among them, the cost of lithium battery is relatively high, the consistency problem still exists; the cost of a liquid flow battery is also high, and lead-carbon battery is a relatively practical and feasible energy storage technology route in the near future.

Ordinary lead-acid batteries have the advantage of low cost, but their short cycle life is short, resulting in higher energy storage costs per unit. Lead-carbon batteries have prevented the sulphation of the negative electrode due to the addition of activated carbon, which prolongs the battery life and reduces the cost per unit of use. It has great potential in the field of new energy storage.

The page contains the contents of the machine translation.