Exploring Electric Battery Technology: A Journey through History, Types and chemistry

Electric battery technology has a rich history dating back to the late 18th century, Electric battery technology has revolutionized the way we power our world, from small handheld devices to electric vehicles and renewable energy storage systems. Understanding the history and various types of electric batteries is essential in appreciating their significance in modern society.

A Brief History Electric Battery

The concept of the battery dates back to the late 18th century when Italian scientist Alessandro Volta created the first true battery, known as the voltaic pile, in 1800. This early battery consisted of alternating layers of zinc and copper separated by cardboard soaked in saltwater, producing a continuous flow of electricity. Volta’s invention paved the way for further advancements in battery technology.

Voltaic Pile (1800): Alessandro Volta invented the first electric battery, known as the voltaic pile. It consisted of alternating disks of zinc and copper separated by cardboard soaked in saltwater or acid. This created a flow of electrons, generating an electric current.

Voltaic Pile

Daniell Cell (1836): Developed by John Frederic Daniell, it improved upon Volta’s design by using a copper pot filled with a copper sulfate solution as the positive electrode and a zinc electrode in a zinc sulfate solution as the negative electrode.

Lead-Acid Battery (1859): Gaston Planté invented the lead-acid battery, which is the oldest type of rechargeable battery still in use today. It consists of lead dioxide as the positive electrode, spongy lead as the negative electrode, and sulfuric acid as the electrolyte.

Nickel-Cadmium Battery (1899): Waldemar Jungner invented the nickel-cadmium battery, which introduced a more efficient and longer-lasting rechargeable battery compared to lead-acid batteries.

Lithium-Ion Battery (1970s-1980s): Stanley Whittingham, John Goodenough, and Akira Yoshino played pivotal roles in the development of the lithium-ion battery, which revolutionized portable electronics and electric vehicles due to its high energy density and low weight.

Types of Electric Batteries

Over the years, battery technology has evolved, leading to the development of various types of batteries, each with its own unique characteristics and applications. Some of the most common types include:

1. Lead-Acid Batteries: Lead-acid batteries are one of the oldest types of rechargeable batteries and are still widely used today, particularly in automotive applications. They consist of lead plates submerged in sulfuric acid electrolyte. Lead-acid batteries are known for their reliability and relatively low cost, making them suitable for starting, lighting, and ignition (SLI) applications in vehicles.
2. Lithium-Ion Batteries: Lithium-ion batteries have gained popularity in recent years due to their high energy density and rechargeability. They are commonly found in smartphones, laptops, electric vehicles (EVs), and renewable energy storage systems. Lithium-ion batteries use lithium compounds as the cathode and typically graphite as the anode. They offer superior performance compared to traditional lead-acid batteries, with higher energy density and longer lifespan.
3. Nickel-Metal Hydride (NiMH) Batteries: NiMH batteries are another type of rechargeable battery commonly used in portable electronic devices and hybrid vehicles. They offer higher energy density compared to nickel-cadmium (NiCd) batteries and are considered more environmentally friendly. NiMH batteries use a nickel oxyhydroxide cathode and a hydrogen-absorbing alloy anode, making them suitable for applications where high energy density and long cycle life are required.
4. Alkaline Batteries: Alkaline batteries are non-rechargeable batteries commonly used in everyday household devices such as remote controls, flashlights, and toys. They utilize zinc and manganese dioxide as the active materials and an alkaline electrolyte such as potassium hydroxide. Alkaline batteries are known for their long shelf life and reliable performance, making them a popular choice for low-drain devices.
5. Solid-State Batteries: Solid-state batteries represent the next frontier in battery technology, offering potential benefits such as improved safety, higher energy density, and faster charging times compared to traditional lithium-ion batteries. These batteries use a solid electrolyte instead of a liquid or gel electrolyte, eliminating the risk of leakage and fire hazards associated with conventional batteries. Solid-state batteries are still in the research and development stage but hold great promise for various applications, including electric vehicles and grid energy storage.

The chemistry of an Electric battery

To produce a flow of electrons, you need to have somewhere for the electrons to flow from, and somewhere for the electrons to flow to. These are the cell’s electrodes. The electrons flow from one electrode called the anode (or negative electrode) to another electrode called the cathode (the positive electrode). These are generally different types of metals or other chemical compounds.

In Voltaic pile, the anode was the zinc, from which electrons flowed through the wire (when connected) to the silver, which was the battery’s cathode. He stacked lots of these cells together to make the total pile and crank up the voltage.But where does the anode get all these electrons from in the first place? And why are they so happy to be sent off on their merry way over to the cathode? It all comes down to the chemistry that’s going on inside the cell.
There are a couple of chemical reactions going on that we need to understand. At the anode, the electrode reacts with the electrolyte in a reaction that produces electrons. These electrons accumulate at the anode. Meanwhile, at the cathode, another chemical reaction occurs simultaneously that enables that electrode to accept electrons.

The technical chemical term for a reaction that involves the exchange of electrons is a reduction-oxidation reaction, more commonly called a redox reaction. The entire reaction can be split into two half-reactions, and in the case of an electrochemical cell, one half-reaction occurs at the anode, the other at the cathode. Reduction is the gain of electrons, and is what occurs at the cathode; we say that the cathode is reduced during the reaction. Oxidation is the loss of electrons, so we say that the anode is oxidised.
Each of these reactions has a particular standard potential. Think of this characteristic as the reaction’s ability/efficiency to either produce or suck up electrons—its strength in an electron tug-of-war.

Any two conducting materials that have reactions with different standard potentials can form an electrochemical cell, because the stronger one will be able to take electrons from the weaker one. But the ideal choice for an anode would be a material that produces a reaction with a significantly lower (more negative) standard potential than the material you choose for your cathode. What we end up with is electrons being attracted to the cathode from the anode (and the anode not trying to fight very much), and when provided with an easy pathway to get there with a conducting wire we can harness their energy to provide electrical power to our torch, phone, or whatever.

Electric Battery Discharge flow diagram

The difference in standard potential between the electrodes kind of equates to the force with which electrons will travel between the two electrodes. This is known as the cell’s overall electrochemical potential, and it determines the cell’s voltage. The greater the difference, the greater the electrochemical potential, and the higher the voltage.

To increase a battery’s voltage, we’ve got two options. We could choose different materials for our electrodes, ones that will give the cell a greater electrochemical potential. Or, we can stack several cells together. When the cells are combined in a particular way (in series), it has an additive effect on the battery’s voltage. Essentially, the force at which the electrons move through the battery can be seen as the total force as it moves from the anode of the first cell all the way through however many cells the battery contains to the cathode of the final cell.

When cells are combined in another way (in parallel) it increases the battery’s possible current, which can be thought of as the total number of electrons flowing through the cells, but not its voltage.

Electrolyte

But the electrodes are just part of the battery. Remember Volta’s bits of paper soaked in salty water? The salty water was the electrolyte, another crucial part of the picture. An electrolyte can be a liquid, gel or a solid substance, but it must be able to allow the movement of charged ions.

Electrons have a negative charge, and as we’re sending the flow of negative electrons around through our circuit, we need a way to balance that charge movement. The electrolyte provides a medium through which charge-balancing positive ions can flow.

As the chemical reaction at the anode produces electrons, to maintain a neutral charge balance on the electrode, a matching amount of positively charged ions are also produced. These don’t go down the external wire (that’s for electrons only!) but are released into the electrolyte.

At the same time, the cathode must also balance the negative charge of the electrons it receives, so the reaction that occurs here must pull in positively charged ions from the electrolyte (alternatively, it may also release negative charged ions from the electrode into the electrolyte).

So, while the external wire provides the pathway for the flow of negatively charged electrons, the electrolyte provides the pathway for the transfer of positively charged ions to balance the negative flow. This flow of positively charged ions is just as important as the electrons that provide the electric current in the external circuit we use to power our devices. The charge balancing role they perform is necessary to keep the entire reaction running.

Now, if all the ions released into the electrolyte were allowed to move completely freely through the electrolyte, they would end up coating the surfaces of the electrodes and clog the whole system up. So the cell generally has some sort of barrier to prevent this from happening.

When the battery is being used, we have a situation where there is a continuous flow of electrons (through the external circuit) and positively charged ions (through the electrolyte). If this continuous flow is halted if the circuit is open, like when your torch is turned off the flow of electrons is halted. The charges will pile/build up and the chemical reactions driving the battery will stop.

As the battery is used, and the reactions at both electrodes chug along, new chemical products are made. These reaction products can create a kind of resistance that can prevent the reaction from continuing with the same efficiency. When this resistance becomes too great, the reaction slows down. The electron tug-of-war between the cathode and anode also loses its strength and the electrons stop flowing. The battery slowly goes flat.

Recharging an Electric battery

Some common batteries are single use only (known as primary or disposable batteries). The trip the electrons take from the anode over to the cathode is one-way. Either their electrodes become depleted as they release their positive or negative ions into the electrolyte, or the build-up of reaction products on the electrodes prevents the reaction from continuing, and it’s done and dusted. The battery ends up in the bin (or hopefully the recycling, but that’s a whole other Nova topic).

Electric Battery Recharge flow diagram

But. The nifty thing about that flow of ions and electrons as it takes place in some types of batteries that have appropriate electrode materials, is that it can also go backwards, taking our battery back to its starting point and giving it a whole new lease on life. Just as batteries transformed the way we’ve been able to use various electrical devices, rechargeable batteries have further transformed those devices’ utility and life spans.

When we connect an almost flat battery to an external electricity source, and send energy back in to the battery, it reverses the chemical reaction that occurred during discharge. This sends the positive ions released from the anode into the electrolyte back to the anode, and the electrons that the cathode took in also back to the anode. The return of both the positive ions and electrons back into the anode primes the system so it’s ready to run again: your battery is recharged.

The process isn’t perfect, however. The replacement of the negative and positive ions from the electrolyte back on to the relevant electrode as the battery is recharged isn’t as neat or as nicely structured as the electrode was in the first place. Each charge cycle degrades the electrodes just a little bit more, meaning the battery loses performance over time, which is why even rechargeable batteries don’t keep on working forever.

Over the course of several charge and discharge cycles, the shape of the battery’s crystals becomes less ordered. This is exacerbated when a battery is discharged/recharged at a high rate—for example, if you drive your electric car in big bursts of speed rather than steadily. High-rate cycling leads to the crystal structure becoming more disordered, with a less efficient battery as a result.

Electric Battery Manufacturers

There are several companies around the world involved in the manufacturing of electric batteries. Here are some prominent ones:

1. Tesla, Inc. (United States): Known primarily for its electric vehicles, Tesla also manufactures lithium-ion batteries through its subsidiary Tesla Energy. They produce batteries for vehicles, stationary storage solutions like the Powerwall and Powerpack, and grid-scale energy storage projects.
2. Panasonic Corporation (Japan): Panasonic is a major supplier of lithium-ion batteries, particularly for electric vehicles. They have a long-standing partnership with Tesla, producing batteries used in Tesla vehicles.
3. BYD Company Limited (China): BYD is one of the largest manufacturers of rechargeable batteries in the world. They produce lithium-ion batteries for various applications, including electric vehicles, energy storage systems, and consumer electronics.
4. LG Chem (South Korea): LG Chem is a leading supplier of lithium-ion batteries for electric vehicles, energy storage systems, and consumer electronics. They supply batteries to numerous automakers, including General Motors, Audi, and Hyundai.
5. Samsung SDI (South Korea): Samsung SDI is a subsidiary of Samsung Group and is involved in the production of lithium-ion batteries for electric vehicles, energy storage systems, and portable electronics.
6. CATL (China): Contemporary Amperex Technology Co. Limited (CATL) is one of the largest manufacturers of lithium-ion batteries for electric vehicles. They supply batteries to various automakers globally and have been rapidly expanding their production capacity.
7. SK Innovation (South Korea): SK Innovation is a major supplier of lithium-ion batteries for electric vehicles. They have partnerships with several automakers and are investing heavily in expanding their battery production capacity.
8. A123 Systems (United States): A123 Systems specializes in lithium-ion battery technology and produces batteries for electric vehicles, energy storage systems, and other applications.
9. Envision AESC (Japan): Envision AESC focuses on producing lithium-ion batteries primarily for electric vehicles. They supply batteries to automakers such as Nissan.
10. Northvolt (Sweden): Northvolt is a European company specializing in the manufacturing of lithium-ion batteries for electric vehicles and energy storage systems. They are building one of Europe’s largest battery manufacturing facilities.

These are just a few examples of companies involved in electric battery manufacturing. The industry is dynamic, with new players emerging and existing players continually expanding their capacities and technologies.

Conclusion

Electric battery technology has come a long way since its inception, with continuous advancements driving innovation and progress in various fields. From the humble voltaic pile to the sophisticated lithium-ion batteries powering our electric vehicles and portable devices, batteries have become indispensable in modern life. As researchers continue to explore new materials and designs, the future of battery technology looks brighter than ever, promising even greater efficiency, sustainability, and reliability. Battery technology continues to evolve, driven by the demand for higher energy density, faster charging, longer cycle life, and improved safety. Advancements in materials science, nanotechnology, and manufacturing processes are key factors in pushing the boundaries of battery technology.