22 Years' Battery Customization
May 05, 2022 Pageview：7076
Lithium-ion batteries charge faster, last longer, and have a higher power density for more battery life in a lighter package.
Since the invention of the first battery or "voltaic pile" in 1800 by Alessandro Volta, batteries have come a long way to provide power to an endless list of portable electronic devices that we all use on a daily basis. The first rechargeable battery was invented by Gaston Planté in 1859 and it was known as a lead–acid battery. In 1980 Sony commercialized the first lithium-ion battery and this new technology has become popular in almost all portable electronic devices including smartphones, tablets, laptops and wearables. A typical lithium-ion battery can generate around 3.6 volts per cell. If you are using a 12 volt lead–acid battery now you will need three lithium-ion batteries to create the same voltage output. Lithium-ion batteries charge faster, last longer and have a higher power density for more battery life in a lighter package.
The weight of a Lithium-ion battery depends on the size, chemistry, and the amount of energy it holds. A typical cell weighs about 30-40 grams. Cells are packaged together to make a battery pack for a device. Batteries for computers, cell phones, and other portable electronics often contain several cells in series (positive to negative) or parallel (positive to positive).
A typical laptop battery contains six cells rated at 3.6V each. For example, a Dell Inspiron 9100 laptop has an 11.1V battery with a capacity of about 4400 mAh (4.4 Ah). This is equivalent to 6 x 3.6V x 4.4Ah = 100 Whr of energy or 1110 g of mass (2.5 lbs).
A 400Whr pack would weigh about 4 kg (8lbs).
As already been mentioned, the weight of a lithium-ion battery pack is not a fixed number. It varies depending on the storage capacity and voltage of the cells in the pack. The most promising way to increase the energy density of batteries is to increase their voltage, but this comes with its own penalties. A smaller, lighter battery can be created by adding more cells to boost the voltage. The only problem is that more cells mean more weight.
As an example, we will use a common 18650 lithium-ion cell found in many laptop computers and electric vehicles. This cell contains about 2 amp hours of charge at a typical voltage of 3.6 V. An electric car that needs 100 kWh of energy would require 14,285 cells to store its charge in these cells alone at 95 percent efficiency. Weighing in at around 50 grams each, this totals up to 714 kilograms (1,574 lbs).
Lithium Ion Battery Weight Calculator
Lithium ion batteries can weigh as little as 3g/Wh, or as much as 8g/Wh. A typical laptop battery weighs between 80 and 120Wh/kg, which means it weighs between 240 and 960g (or .5 to 2 pounds). A typical smartphone battery might weigh around 20-40g.
This lithium ion battery weight calculator is an extremely lightweight and simple-to-use tool, which will help you find the approximate weight of a li-ion battery based on its specific energy, density and volume. In this article, we'll present an explanation of how a calculator works. This calculator will tell you the battery weight of your lithium ion battery pack. It can help you determine if your battery is too heavy or not heavy enough. For each cell, enter the mAh and the Volts. If you don't know the mAh and Volts of your battery, please check with your manufacturer for the specs.
As engineers, we are often asked to quickly estimate the weight of a battery pack. While it is easy to provide a ballpark weight for simple chemistries like nickel metal hydride (NiMH) and lead acid, the large number of potential formulations in lithium ion chemistry makes this more difficult.
The first step in calculating the weight of a lithium ion battery pack is to determine its capacity in amp-hours (Ah). This is typically provided by the product specification for off-the-shelf batteries or by dividing the total energy (in Watt-hours) by the nominal voltage if designing custom packs.
Next, we need to look at the specific energy of our battery chemistry. The following table provides approximate values for common formulations:
Lithium Ion Chemistry Specific Energy (Wh/kg)
Lithium Cobalt Oxide (LCO) 140 - 175
Lithium Manganese Oxide (LMO) 115 - 145
Lithium Iron Phosphate (LFP) 95 - 120
Lithium Nickel Manganese Cobalt Oxide (NMC) 115 - 150
If you are using an off-the-shelf battery, it is possible that your manufacturer has published specific energy information. Otherwise, we can estimate a value based on our chemistry. For example, a Lithium Manganese Oxide battery with a nominal voltage of 3.6V and 120 Wh/kg specific energy would have 33 Ah of capacity and weigh 1kg.
Lithium Ion Battery Weight Density
Energy density is a key parameter for batteries. This can be expressed in terms of specific energy (energy per unit mass) or energy density (energy per unit volume), but for batteries the two are closely related.
It's not immediately obvious why energy density is important, but consider that a vehicle running on gasoline has to carry around its fuel; if it carries more fuel, it can go further. So by increasing the energy density of its fuel, you can make a vehicle lighter and more efficient. The same applies to an electric vehicle: because it carries its battery around with it, a higher-density battery means a lighter vehicle.
As we've already seen, lithium-ion batteries have much higher power densities than their predecessors. But they also have much higher specific energies - typically 150 Wh/kg compared to 50 Wh/kg for lead acid batteries and 70-90 Wh/kg for nickel metal hydride types.
In fact the specific energies of lithium-ion batteries are comparable to those of gasoline. So why don't electric vehicles have ranges comparable to gasoline vehicles? Surely that would mean that gasoline has less than half the specific energy of lithium ion? No - it turns out that modern gasoline engines are about 40% efficient, so a cell with 150 Wh/kg could give an EV with 60% drivetrain efficiency a range comparable to a gasoline vehicle.
The specific energy of gasoline is about 12 kWh/kg, which represents a volumetric energy density of about 32 kWh/l. Lithium ion batteries have an energy density of around 160 Wh/kg, which is 0.16 kWh/kg.
This 12:0.16 ratio translates to an equivalent volumetric density of 76.8 kWh/l. The Tesla Model S has a battery pack with a capacity of 85 kWh and weighs 540 kg; this gives it a volumetric energy density of 0.39 kWh/l - about 5% of the equivalent for gasoline.
So why do electric vehicles have significantly lower ranges than their gasoline equivalents? There's no fundamental reason why they should be limited in this way - the problem is that practical battery packs are still much too heavy and cumbersome to enable electric vehicles to compete with gasoline ones on range.
This isn't just a question of technology: even if we had batteries with the same energy density as gasoline (and we don't), we'd still need to find ways to reduce the weight and volume taken up by other components in the car - everything from tyres to axles to engine mounts needs to be much lighter if we want electric vehicles that can challenge their gasoline equivalents in terms of range.
Lithium Ion Battery Weight Breakdown
A lithium ion battery is made up of several different components: the cathode, anode, separator, electrolyte, and current collector. The chemistry of the cathode and anode determine the type of lithium ion cell (e.g. LiCoO2, LiFePO4, etc.) and thus the capacity, rate capability, safety characteristics, and cost of the cell. The typical cell configuration in a vehicle is prismatic or cylindrical with a capacity between 20-85 Ah.
The cathode material makes up roughly 30% of the mass of a lithium ion battery cell. The anode makes up roughly 30% of the mass as well. The separator accounts for 15%, while the current collector is just under 10%. Electrolyte (including additives) makes up about 2% by mass and everything else accounts for roughly 13%.
The weight breakdown of a Lithium ion battery pack is as follows (Kokam data):
Cell - 48%
Packaging - 25%
Other (cables, connectors, contactors, etc.) - 9%
Cooling System - 5%
Battery Management System - 5%
Hardware/Support Structure - 4%
Safety Systems - 2%
Miscellaneous (fans, electrical components) - 2%
Conclusion
Lithium-ion batteries are often regarded as the best type of rechargeable battery for portable electronics. They have one of the best energy densities, no memory effect, and low self-discharge. For these reasons, lithium-ion batteries are used for a wide range of portable electronics.
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