The solution resides within an intriguing, concise chronicle of tech advancements and the dynamics of the marketplace.
Upon a cursory examination of your utility drawer, you may recognize a diverse assortment of batteries, each differing in size, shape, and type, all engineered to power various gadgets. The compact, circular, non-refillable button cells comfortably fit in your watches and smaller items. Meanwhile, the well-known AA and AAA cylindrical batteries cater to powering calculators, clocks, and remote controls. There are also rechargeable lithium-ion batteries for your laptops and phones. And let’s not forget the crucial lead-acid battery that keeps your car running.
As an academic focusing on battery studies and electrochemistry, I can tell you that the reason batteries are so varied in their attributes and functionality traces back to their historical development and evolution.
The birth of batteries dates back to the 1800s, with the original models being rather rudimentary. As an example, one of the initial demonstrations consisted of metallic discs steeped in brine, which was found by Italian scientist Alessandro Volta to generate an electric current. The first-ever lead-acid battery was simply made up of a few lead pieces immersed in a jar filled with sulfuric acid.
Despite the developments, contemporary versions are not drastically different. They are merely more efficient to produce and include various additives to enhance their performances.
Fundamentally, all batteries operate on the same principle: a voltage disparity between two unlike electrodes is responsible for creating an electric current, which can be used to power a device. Batteries that can be recharged have the ability to reverse this current to recharge. Within the battery, the electric current is carried along with the flow of ions through a liquid, known as the electrolyte.
Associated with the passage of each electron in the current is the transportation of one ion through the electrolyte. This process is essential because electrodes capable of storing more ions result in batteries that can store and therefore deliver more charges, providing longer usage per charge. When electrodes are designed for quick ion storage, it results in batteries capable of discharging rapidly, suitable for high-power applications. Lastly, the ability to charge and discharge without deteriorating leads to batteries with an extended lifespan.
Pioneering Rechargeable Batteries: Lead-acid Batteries
Tracing back to 1859, the lead-acid battery stands as a paramount invention in the field of rechargeable batteries. Gaston Plante, a pioneer, put lead plates in an acid solution, and discovered that he could manipulate the flow and storage of electric current in a reversible manner.
The size of a lead-acid battery plays a significant role in determining its efficacy. Its dimensions need to satisfy the requirement of generating sufficient power to initiate a car’s function. Additionally, it must withstand the harsh conditions typical of colder climates and endure for extended periods. The electrolyte used in its structure is a corrosive acid, which necessitates a robust external casing to safeguard humans and automobile components against potential damage. Consequently, it’s logical to find that contemporary lead-acid batteries exhibit a hefty and cubic architecture.
Alkaline Batteries
Conversely, everyday household gadgets such as calculators and digital scales typically utilize smaller batteries, given their lower energy demand. The mainstay in these devices are the non-rechargeable alkaline batteries that have stood the test of time. These batteries come in standardized cell sizes, including AAAA, AAA, AA, C and D, along with button, coin cells, and many others.
The sizes of these batteries correspond directly to their energy storage capacity – larger batteries can store more charge. This also dictates the sizes of the devices they power.
Alkaline batteries occasionally come in a rectangular format, reminiscent of the ubiquitous 9-volt batteries. However, upon opening the outer shell, one would find several cylindrical cells joined together internally. The longevity and extensive use of cylindrical batteries have made them a steadfast choice for manufacturers, as it makes little sense to alter established production processes, an effort that would require significant investment.
Ion Batteries Powered by Lithium
For multiple years, nickel-cadmium batteries led the pack as the primary choice for rechargeable batteries for household electronics. They remained in the limelight until the turn of the 21st century. However, these batteries had significant drawbacks. They were composed of cadmium, a highly toxic element, and suffered from a “memory effect,” which shortened their lifespan.
Lithium was extensively examined for possible utilization in rechargeable batteries over many decades due to its exclusive properties. As a light metal, it holds a significant amount of energy. In 1991, Sony was the pioneer in bringing the lithium-ion battery to the commercial market.
Initially, Sony opted to create cylindrical cells since they were the simplest to manufacture. Given that Sony produced a plethora of camcorders and tapes during the 1990s, it possessed a substantial amount of roll-to-roll manufacturing tools. The company found it logical to reassign this equipment in order to fabricate battery electrodes, constructed through film casting on copper or aluminum sheets and then twirled into a cylindrical shape that resembles a “jelly roll”.
The robust and thick casing of these cylindrical cells provides mechanical strength, and they are further safeguarded with a pressure relief valve. In no time at all, these initial lithium-ion cells dominated the portable electronic market, particularly in laptops and cell phones, as they offered more energy storage and longevity compared to their nickel-cadmium counterparts.
The crafting of batteries
The design and configuration of batteries are influenced not only by cost-effectiveness and ease of production but also by traditional manufacturing procedures. Market needs are another major determinant.
For instance, the success of electric vehicles was largely determined by Tesla’s innovative approach of using cylindrical lithium-ion battery cells, unlike other manufacturers who stuck to rectangular pouch or prismatic cells. The choice of cylindrical cells, which were already being produced on a large scale for handheld gadgets, allowed Tesla to manufacture economical electric vehicles in the 2010s.
The potential shapes and dimensions of future batteries depend not just on their energy storage capacity, but also on the market dynamics — the simplicity of producing each cell variant, the production costs, and their intended uses. This combination of pioneering technology and historical influences shapes the evolution of battery designs.
