Rachid Yazami is a Moroccan scientist and engineer. He is best known for his critical role in the development of the lithium-ion battery, as the inventor of the graphite anode of lithium-ion batteries. He is also known for his research on fluoride ion batteries. In 1980 Yazami was the first scientist to establish the reversible intercalation of lithium into graphite in an electrochemical cell using a polymer electrolyte. Eventually, his discovery led to the lithium-graphite anode now used in commercial lithium ion batteries. Yazami also worked on other forms of graphite materials for cathode application in lithium batteries, including graphite oxide and graphite fluoride.
Rachid Yazami is sharing with the world one of his recent inventions, a way to facilitate early detection of short circuits in batteries, that could save the lives of many.
The invention is a method that the Moroccan scientist developed to detect the early stages of short circuits inside phone batteries and other device batteries to avoid explosions and fire.
In an interview with Morocco World News, Yazami emphasized that the battery field still has no “reliable methods to detect early stages of short circuit inside the battery.” This inspired his invention.
Before detailing his invention, the scientist provided technical insight into how an explosion or a short circuit could occur. Yazami agrees that the quality of a battery plays a crucial role, but even good quality batteries could be a threat. He explained that heat generation sometimes translates to increasing the internal pressure “inside the battery and there is flammable gas called the solvent of electrolytes that ignites and starts a fire or explosion.”
The scientist said that there could be many reasons for this type of explosion. One is if the users are relying on an inappropriate “charger that does not have probes to check on the battery’s temperature and also of the voltages of the cell.”
Yazami argued that if the users are overcharging and they are not controlling the temperature, the battery could catch fire because of a low quality charger. His invention would help mitigate such occurrences by allowing users to monitor overheating independently.
The award-winning expert explained that the most common cause of batteries catching fire is due to an “internal defect in the battery that can grow as you are charging and discharging [the] battery in time.”
How short circuits occur
Yazami explained that the short circuit could start on a small level, which would make its detection difficult. “The short circuit current is very low and that can be impossible [to] detect either by measuring the voltage of the battery or measuring the temperature.” The separator between the two structures could melt due to high temperatures.
As it melts, the contact surface between anodes and cathodes increases and as a result the short circuit current increases, too. “When the temperature gets higher, the evaporation of organic liquid is higher. Suddenly [the] battery releases gases. Once these gases [make] contact with air, the battery catches fire.” The event could go so far to cause an explosion with the potential to claim several lives. This is where Yazami’s invention comes into play.
Early stage detection is important
The Moroccan scientist explained that he developed a method to enable people to detect very early stages of internal short circuits. “I have a system consisting of a chip. This chip is inside the battery, and it collects data, like voltage temperature of the cell, and basically it converts the data to useful information to analyze the battery and compare to batteries that have no short circuit,” the inventor said.
The data collector shows signals and highlights the difference between the signals if the battery has a short circuit or has no circuit.
“My method could let people detect the short circuit in an early stage to help people stop using it” to avoid a tragedy. “My invention is for good quality chargers and batteries,” he added, indicating that even in the best-case-scenario, good devices degrade in quality over time and can still present risks.