Characteristics of traditional lead storage batteries
According to different application scenarios, the characteristics of traditional lead storage batteries are different.
Although there are many types of traditional lead storage batteries, they also have some common features. Among them, the main advantages of traditional lead storage batteries are as follows:
(1) The traditional lead storage battery has good safety (the electrolyte is dilute sulfuric acid, no danger of explosion and flammability), high battery consistency, large single battery capacity, wide operating temperature tolerance range (-30~50℃), high current performance and good cycle performance. At present, the batteries used for energy storage are mainly advanced sealed valve-regulated batteries. Among them, colloidal batteries are widely used in energy storage because of their good temperature resistance, low self-discharge rate, low water loss rate, and long cycle life (100% D0D can reach more than 800 times, and the tubular gel battery with the positive plate is a tubular structure can reach more than 2000 times).
(2) The technological advantages are obvious, the traditional lead storage battery industry chain structure is complete, and the production equipment is mature and advanced.
(3) The price is cheap. The main raw materials are lead, sulfuric acid, plastics, etc. The raw material resources are abundant, cheap and stable.
(4) The economic benefit of recycling is extremely high, the battery can be recycled 100%, the recycling processing technology is mature, the recycling processing equipment is advanced, and the recycling rate can reach more than 96%. The recycling discount of used batteries can reach more than 40% of the cost of new batteries, and the overall recycling economic benefit is the highest among all batteries.
However, traditional lead storage batteries also have their disadvantages:
(1) The charging speed is slow, generally need more than 8h.
(2) Due to the high density of lead, the specific energy and specific power are low.
(3) Affected by the softening of the positive lead paste, the corrosion of the grid, and the irreversible vulcanization of the negative electrode, the cycle life is low (300~500 times).
(4) Affected by the vulcanization of the negative electrode, the high current pulse charge and discharge performance is poor.
(5) Overcharging is easy to release gas.
(6) The overflow of sulfuric acid will pollute the environment.
Characteristics of super batteries
Super batteries are essentially lead storage batteries, and their main features include:
(1) The charging and discharging speed is fast and the power density is high. Super battery is a combination of lead battery and super capacitor. Due to the combination of high power characteristics of super capacitor, the power density of super battery is higher than that of ordinary AGM valve regulated lead battery. Figure 1 is a graph showing the relationship between the charge and discharge capacity of a super battery and DOD (depth of discharge). As can be seen from the figure, under the same D0D, the discharge capacity of the super battery is at least 1 times higher than that of the ordinary lead storage battery, and the charging capacity is increased by 60%. The power density data given by Furukawa Battery Company and CSIR0 is 500~600W/kg.
(2) In the case of high-rate charge-discharge at half state of charge (ie, HRPSOC conditions), the battery life is far longer than that of traditional lead storage batteries. HRPSOC is mainly aimed at three applications: hybrid electric vehicles, grid frequency regulation and new energy grid-connected power balance. The U.S. Department of Energy’s Sandia National Laboratory began third-party testing of super batteries in 2008, and the test results are shown in Figure 2. In the grid power application test project, Sandia National Laboratories commented that: “EastPerm’s high-capacity super battery for wind power balance works well, with a significant improvement in HRPSOC cycle life compared to common VRLA batteries.”
(3) The deep cycle life is nearly 10 times longer than that of ordinary lead storage batteries. At the 13th Asian Battery Conference held in September 2009, Furukawa Battery Company disclosed the latest progress of its super battery development. The long-life deep charge and deep discharge super battery developed by the company has achieved a cycle life of more than 6,000 cycles, while the life of ordinary lead storage batteries under the same conditions is only about 500 cycles. In addition to the data from Furukawa Battery, the U.S. Department of Energy’s Sandia National Laboratory has conducted a solar energy storage deep cycle application test project on super batteries since 2009, and super batteries have also shown performance advantages far exceeding that of ordinary lead storage batteries.
(4) Super battery belongs to the improved technology of lead battery, so it retains the advantages of low cost, recyclability and good safety of lead battery.
However, there are some disadvantages of super battery:
(1) Due to the carbon-containing material in the negative electrode, the battery has higher requirements for water loss control, and the advantages in the long-term floating charge application field are not obvious, the anti-overcharge ability is reduced, and it is more sensitive to the working environment (high temperature condition).
(2) Like traditional lead storage batteries, there are certain challenges in environmental protection.