Goodenough’s Li-ion battery
Photo Source: Johan Jarnestad/(The Royal Swedish Academy of Sciences)
Lithium is the lightest metal and has the highest electrochemical potential which make it an ideal material for batteries. In 1970s, researchers began considering
lithium as a viable material for rechargeable batteries. Stanley Whittingham, a chemist, is often credited with pioneering the development of the lithium-ion battery. In the 1970s, while working at Exxon, Whittingham focused on creating energy storage solutions. He discovered that lithium ions could move from one electrode to another within a cell, leading to the creation of the first functional lithium battery. His design used a lithium metal anode and a titanium disulfide cathode. He created the first lithium-ion battery in 1976 with metallic lithium at the anode and titanium disulfide intercalated with lithium ions at the cathode. The battery had an electromotive force (EMF) of 2 volts.
Whittingham’s Li-ion battery.
Photo Source: Johan Jarnestad/(The Royal Swedish Academy of Sciences)
However, Whittingham’s lithium battery had limitations. The use of metallic lithium raised safety concerns due to its tendency to form dendrites, which could cause short circuits and potentially lead to fires or explosions. This led to further research to find safer alternatives.
In the 1980s, John B. Goodenough, a professor at the University of Texas at Austin, and his team made a groundbreaking discovery. They found that using a lithium cobalt oxide cathode instead of metallic lithium could significantly improve the battery’s safety and performance. This discovery laid the foundation for the modern lithium-ion battery.
Further advancements in the 1990s and early 2000s led to the commercialization of lithium-ion batteries. Companies like Sony, with the introduction of the first commercial lithium-ion battery in 1991, played a crucial role in bringing this technology to the market. Since then, lithium-ion batteries have become ubiquitous, powering everything from smartphones and laptops to electric vehicles and grid-scale energy storage systems.
The key components of a lithium-ion battery include the cathode (typically made of lithium cobalt oxide), the anode (often graphite), and the electrolyte (a lithium salt dissolved in a solvent). Its work based on the movement of lithium ions between the positive and negative electrodes. The anode is rich in lithium ions when the battery is charged. The two electrodes are separated by a porous material soaked in an electrolyte solution, usually a lithium salt dissolved in solvent. The electrolyte allows the movement of lithium ions between the electrodes while preventing direct contact between them. When charging, a voltage is applied across the battery terminals, causing lithium ions to move from the positive electrode (cathode) through the electrolyte and become embedded in the negative electrode (anode). This process is called intercalation. During this, electrons are released from the negative electrode and flow through the external circuit, providing electrical energy. When the battery is connected to a load, the opposite process occurs. Lithium ions move back to the positive electrode (cathode) through the electrolyte, releasing electrons in the process. These electrons flow through the external circuit, creating an electric current that powers the device. The movement of lithium ions between the electrodes is reversible, meaning it can occur back and forth during charging and discharging cycles. This reversibility allows lithium-ion batteries to be rechargeable.
The evolution of lithium-ion battery technology continues today, with ongoing research aimed at improving energy density, safety, and cost-effectiveness. As the demand for energy storage solutions grows, lithium-ion batteries remain at the forefront of innovation, driving advancements in renewable energy integration, transportation electrification, and portable electronics.
-Ayush Poudel
Ankuram Academy (2023)
