I was casually swiping on my Facebook news feed when I accidentally opened a video containing a scene from a very popular TV series, It was not that special, the guy just made his own battery from some common materials and it worked! Since I am quite familiar with the most common types of batteries, and also an employee of a company that sells batteries(technically) I decided to write a blog about it. This blog will basically cover the common types of batteries, their applications, and their over-all performance. I will do my best not to complicate things when discussing it.
Let’s have a brief history lesson, The first battery was invented by Alessandro Volta in Italy, circa 1800 - Yes batteries have been around for that long; His colleague Luigi Galvani was experimenting with a dead frog when he accidentally brushed his dissecting device to its leg, this made the frog move,he called this animal electricity believing that it came from the frog itself, however, Volta insisted that it was rather the metal of his dissecting device that caused the electrical surge, To prove this, he modeled the first battery popularly know as voltaic plate, and yes the term “Volts(value of electrical pressure)” is coined after him. There are even evidences suggesting that they could be older; While doing some railway works in Baghdad, 1936, workers have accidentally unearthed a jar that appeared to be a prehistoric battery. It was believed to have come from the Parthian Empire and is already 2000 years old. Interesting right? That’s the end of our brief history lesson, We will now proceed to our brief science lesson.
How does a battery work? - It converts chemical energy into electricity, This is the simplest explanation I can come up with. Going deeper into the details, a battery has 3 necessary parts,a cathode, an anode, and a battery solution;The liquid battery solution was then replaced in dry cells with paste as time goes by the paste was replaced with other materials but still retains the same working principle; The anode, being the negative side of the battery, sends electrons to the cathode when they are in-contact in process known as oxidation, the electrons received by the cathode are then absorbed by the ions on the battery solution in the process known as reduction. During that time, this process was quite inefficient since batteries can only be used once, thus, scientists discovered a way in how to re-use batteries, hence, rechargeable batteries entered the market.
To date, there are 2 main types of batteries, 1.Primary batteries and 2. Secondary batteries; Primary batteries are those you can only be used once, once depleted, they cannot be recharged, thus, they go to trash, they still are in market right now, they are applicable in devices that doesn’t need a lot of power or in any other application that would deem recharging unnecessary. Next are the secondary batteries, the ones that can be recharged, we will elaborate this one much better because modern devices are dependent on this technology. There are several types of secondary batteries, Here are the most common:
1.Lithium-Ion(Li-Ion)
2.Nickel Cadmium (Ni-Cd)
3.Nickel-Metal Hydride (Ni-MH)
4.Lithium-Polymer(Li-Po)
5.Lead Acid
Fig1. Lithium-Ion batteries
Lithium-Ion batteries is probably the most popular at present, they can be found in a variety of modern devices like smart phones, laptops, and etc. and even in military applications. Its working principle is just the same with the original design but the materials it uses is different so as its performance. Li-Ion batteries tend to have higher energy density, little to no memory effect, and has a lower discharging rate compared to the others.[1] Here are some Li-Ion specs that I have found in the internet:
- Specific Energy: 100 - 265W-h/kg
- Energy Density: 250 - 693 W-h/L
- Specific Power: ~250 - ~ 340 W/kg
- Charge/discharge percentage: 80-90%
- Cycle Durability: 400 - 1200 cycles
- Nominal cell voltage: NMC 3.6/3.7/3.8/3.85V
Fig2. Nickel-Cadmium batteries
Nickel-Cadmium batteries are also one of the most common type of batteries, although they are not that popular at present, they were once used in applications that requires a compact power source. It was very excellent in holding up its rated voltage and can hold its charge when not in use. Also, they tend to perform very well when delivering at full capacity. However, this type of battery has a significant downsides, it has a very high vulnerability to the memory effect -A condition that shortens the lifespan of a battery when they’re not charged properly.[2] Here are some specifications:
- Specific Energy: 40-60W-h/kg
- Energy Density: 50-150 W-h/L
- Specific Power: 150W/kg
- Charge/discharge efficiency: 70-90%
- Self-discharge rate: 10%/month
- Cycle durability/life: 2000 cycles
Fig3. Nickel-Metal Hydride batteries
An improved version of the Nickel-Cadmium battery is the Nicke-Metal Hydride type. The most significant difference between the two is that Ni-MH uses hydrogen absorbing alloy for its negative electron instead of cadmium and also, its composition does not get affected by memory effect as much as its predecessor. Ni-MH batteries were outstanding during its time, it was praised for its high capacity and high energy density, almost at par with the more modern Li-ion batteries.[1]
- Specific Energy: 60-120 Wh/kg
- Energy Density: 140-300 Wh/L
- Specific Power: 250-1000 W/kg
- Charge/discharge efficiency: 66% - 92%
- Self-discharge rate: 13.9-70.6%/month at room temperature
- Cycle Durability/life: 180 -2000 cycles
Fig.4 Lithium Polymer batteries
Lithium-polymer or Li-Po batteries are just mutated Lithium-ion batteries. Instead of using lithium salt as electrolytes(battery solution) They instead use solid polymer electrolytes, can be described as gel like substance. They are also very popular just like its Lithium-Ion predecessors, they are widely used in applications where weight is a critical factor.[1]
- Specific Energy: 100-265 Wh/kg
- Energy Density: 250 -730 Wh/L
Fig5. Lead-Acid battery
Last but not the least, is the Lead-Acid battery, the oldest of its class, Widely used for high capacity applications such as automotive, solar PV systems, and backup power system. It is very important to note that they are quite heavy, thus, we have to remove them from the portable division.[5]
- Specific Energy: 35 - 40 Wh/kg
- Energy Density: 80 - 90 Wh/L
- Specific Power: 180 W/kg
- Charge/discharge efficiency: 50% - 95%
- Self-discharge rate: 3-20%/month
- Cycle Durability/life: <350 cycles
I think we have already discussed all the necessary topics for this blog. Technology is still evolving and the future of energy storage is very bright, Especially that batteries are becoming more and more complementary to our modern lifestyle. The advent of electrical cars’ popularity is also one of the key factors that is bringing the battery world in to research frenzy, Scientist from all over the world are on the race to find the next advancement in battery technology.
SOURCES:
[1]https://en.wikipedia.org/wiki/Lithium-ion_battery
[2]https://en.wikipedia.org/wiki/Nickel%E2%80%93cadmium_battery
[3]https://en.wikipedia.org/wiki/Nickel%E2%80%93metal_hydride_battery
[4]https://en.wikipedia.org/wiki/Lithium_polymer_battery
[5]https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery
Some technical terms used::
Specific energy - Energy density per unit mass. We can technically describe it as how much energy can an object(battery) carry when it weighs “N” kg/lbs
Energy density - Almost the same with specific energy but this time its per unit volume.
Specific power- Amount of power(wattage) that an object can carry per per unit mas.s.
Charge/discharge percentage- The amount charging current compared to the discharging current
Cycle durability - How many times a battery can be recharged before experiencing issues
Memory effect - A condition where a battery loses its rated capacity after not properly charging it. Ni-Cd and Ni-MH have the highest memory effect manifestation.
-Paul Custan is an Electrical Engineer who have worked as a software engineer and as a digital platform specialist before becoming a full-time FNX Solar employee. FNX Solar Power Solutions Inc. is a business based in Canada. We develop and sell portable power stations and related accessories.