Lead-carbon battery is a new type of Polymer Power Bank-battery, is a combination of lead-acid batteries and supercapacitors. This not only played the advantages of instantaneous large capacity supercapacitor charging, but also played a lead-acid battery than the energy advantages, and has very good charge and discharge performance. Due to the addition of carbon (activated carbon, graphite and carbon black), to some extent, to prevent the phenomenon of negative sulfate, to improve the battery failure in the past a factor, but also extend the battery life.
Negative sulfation mechanism
· The main problems faced by the battery and C & D's solution:
The main problems that occur with the negative Polymer Power Bank battery are: Sulfation of active substances. The main outcome is the use of carbon technology to adjust.
The main problems that appear on the battery positive are: Corrosion of the positive grid. C & D's unique positive design is suitable for recycling applications with reduced corrosion.
Different types and basic characteristics of carbon
· C & D carbon technology to improve battery performance
1, to improve the extreme temperature tolerance;
2, improve the charge acceptance;
3, greatly reduce the speed of the sulfation in PSoC operation, improve cycle performance, extend battery life under PSoC;
4, improve the battery deep cycle performance.
· C & D carbon battery performance characteristics
1, C & D carbon battery's low temperature characteristics
C & D carbon batteries have better low-temperature discharge performance than liquid-rich batteries and conventional common VRLA batteries. Carbon materials have a very large available surface, as shown.
As shown in the above figure, a common lead-acid battery can only discharge 50% of the rated capacity at -20 degrees, while a C & D carbon battery can emit 66% of the rated capacity at the same temperature. This means that C & D carbon batteries offer up to 16% more capacity than ordinary lead-acid batteries at -20 degrees.
Low-temperature battery selection in the customer's benefits, one is the same capacity output requirements, smaller battery size, saving floor space. The second is to provide more power output, fewer batteries, save related accessories. The third is in the same size, compared to ordinary lead-acid batteries, can provide a longer standby time.
2, C & D carbon battery temperature characteristics
C & D carbon batteries have excellent thermal management properties due to the good thermal conductivity of carbon / graphite.
C & D carbon batteries not only emit their own heat, but also absorb heat from the positive plate and the battery. Therefore, a battery made of a carbon-reinforced electrode can rapidly conduct heat out of the battery when an electrochemical reaction occurs to generate heat. This drastically reduces the possibility of thermal runaway compared to conventional lead-acid batteries, enabling the battery to operate at a cool and suitable temperature.
3, C & D carbon batteries: charge acceptance
Integrated carbon carbon battery can accept the maximum charge current is 300% of ordinary lead-acid batteries. Example: C & D Carbon 5hrs vs. Ordinary lead-acid battery 10hrs @ C15min discharge, 100% charge; C & D carbon battery 10 hrs vs. Ordinary lead-acid batteries> 17hrs @ C / 10 discharge, 100% charge Charging time reduced by 50%, as shown below.
C & D carbon battery: charging time and depth of discharge
Part of the state of charge (PSoC) operation
Batteries need to be able to charge efficiently with high efficiency; charging for a limited time at a float voltage causes the battery to operate at PSoC, VRLA to run repeatedly under partially charged conditions, Lead to "irreversible" capacity loss, whereas PbSO4 crystals formed on the negative electrode recrystallize to form "hard sulfates" (ie, large grains of low surface area) that are difficult to convert to lead (Pb) under normal and operating conditions In addition, the Ericsson test simulates a typical partial state-of-charge (PSoC).
1. 39.0WPC (6 hour discharge rate) discharge 2 Hours (33% DOD)
2. 2.27VPC charging 2 Hours
3. 39.0 WPC discharge 3 Hours (50% DOD)
4. 2.27VPC charge 4 Hours
5. 39.0WPC discharge 5 Hours (83% DOD)
6. 2.27VPC charge 8 Hours
7. Repeat the above six steps (average depth of discharge more than 55%)
· C & D carbon battery excellent cycle performance (25 degrees and 35 degrees)
· C & D carbon battery features summary
1, Lead carbon Polymer Power Bank battery discharge depth of 60%, can be recycled for more than 3,000 times. (C & D Lead Carbon Battery 30% -80% PSoC Test The measured cycle performance has been cycled more than 4,300 cycles since June 2012. The test is still not over.C & D tested at Ericsson for 3 cycles a day with discharge depths of 33% 50% / 83%, average depth of discharge more than 55%, circulated over 1,450 days, 4,350 times and the test has not yet ended.
2, lead carbon batteries in partial state of charge (PSoC), can inhibit the production of negative sulfate, the battery will not fail due to insufficient charge. Note: Sulfate crystallization at the anode is one of the causes of the failure of a VRLA battery.
3, lead carbon battery operating temperature range is very wide: -23 ℃ to 60 ℃.
4, lead-carbon batteries add carbon, carbon has a good thermal conductivity, so lead-carbon batteries for high-temperature work.
5, low-temperature lead-carbon battery discharge performance than the traditional lead-acid batteries. The conventional lead-acid battery discharge capacity of only 50% at -20 ℃, lead-carbon batteries at the same temperature discharge capacity of up to 66%.
6, the traditional lead-acid batteries can only be charged at 0.2 C (standard charge is 0.1C). Lead-carbon batteries can accept maximum 0.6C charge, charging current is 3 times the traditional lead-acid batteries can greatly shorten the charging time, especially for unstable solar charging system.
7, C & D Most of the lead-carbon batteries are front-end batteries or horizontal batteries, the battery in the front wiring, easy maintenance. No need to maintain space between the battery layer and the layer, can save a lot of installation area. (C & D lead-acid batteries save up to 30% or more of installation area on containers than other brands.)
In summary, lead-carbon batteries improve battery performance, and have some advantages in Polymer Power Bank battery performance characteristics, such as high temperature and low temperature characteristics, charge and discharge depth, and cycle performance. Compared with lithium batteries, although lithium batteries are slightly better in terms of volume, weight, specific energy, discharge rate and number of cycles, lead-carbon batteries are more secure, recyclable and reusable. In the battery management system (BMS), lead-carbon batteries do not require excessive monitoring system. The most important is that lead-carbon batteries cheaper, lithium batteries about 2.5 times the lead-carbon batteries, lead-carbon batteries better value for money. In the peak load storage applications, lead-carbon batteries have economic value, investment recovery period of about 5-6 years. Compared with colloidal batteries, lead carbon batteries have the advantages of greater advantages in volume, the number of cycles, part of the state of charge, charging capacity and the negative will not produce vulcanization and other advantages, lead carbon batteries are solar and wind energy Renewable energy such as the best smooth fluctuations in energy storage products. In short, lead-carbon Polymer Power Bank batteries, although there is room for improvement (C & D second-generation lead-carbon batteries are in the pilot phase), but its advantages can not be ignored, is one of the types of battery research and development.