The introduction of lithium batteries has transformed portable electronics and electric vehicles by offering a small and effective power supply. However, a significant problem that has arisen with these developments is thermal runaway, a situation where a battery experiences unmanageable self-heating, resulting in severe consequences.
In this article, we investigate the complex internal chemical reactions of lithium batteries, examining the reasons and outcomes of thermal runaway. Additionally, we present an innovative gas-based early warning system to identify and address this potentially hazardous event.
Research on the Internal Chemical Reaction of Lithium Batteries:
Understanding the complexities of thermal runaway requires a grasp of the internal chemical reactions in lithium batteries. The theoretical basis, structure, and operational principles of lithium batteries form the basis for this examination. Within the battery, three main chemical reactions take place: between the positive electrode and electrolyte, between the negative electrode and electrolyte, and within the electrolyte itself. It is crucial to identify the solid and gas products of each reaction and comprehend the associated heat release.
The reaction between the positive electrode and electrolyte involves intricate processes that contribute to the overall energy storage and release mechanisms. Similarly, the reaction between the negative electrode and electrolyte plays a crucial role in the operation of lithium batteries. At the same time, the electrolyte itself undergoes chemical changes that impact the overall stability and performance of the battery. By analyzing these reactions, researchers gain valuable insights into the factors contributing to thermal runaway.
Trigger Sequence of Chemical Reactions:
Understanding the sequence of chemical reactions is crucial for predicting and preventing thermal runaway. Researchers have identified a series of reactions triggered at various temperatures, from solute decomposition at low temperatures to diaphragm dissolution at high temperatures. This sequence involves the rupture of the Solid Electrolyte Interphase (SEI), reactions at the negative and positive electrodes, adhesive decomposition, and diaphragm dissolution.
By examining the order of these reactions, scientists can identify the temperature ranges where thermal runaway is more likely to occur. This knowledge is essential for developing effective early warning systems and preventive measures to protect lithium battery applications.
Early Warning and Diagnostic Strategy:
One innovative method for reducing the risks of thermal runaway is the creation of a gas-based early warning system. This novel approach utilizes the unique characteristics of gases produced during regular battery operation compared to those generated during thermal runaway, including differences in content, rate of change, and type.
Implementing this strategy involves incorporating specialized sensors capable of detecting and analyzing the gases released by lithium batteries. By establishing specific thresholds for gas content and change rates, researchers can create a dependable diagnostic system that can detect abnormal conditions signaling an imminent thermal runaway.
The selection of suitable sensors is a crucial aspect of this strategy. High-precision sensors that can accurately distinguish between normal and abnormal gas emissions are essential for the effectiveness of the early warning system. Additionally, setting precise thresholds ensures that false alarms are minimized while still providing a timely warning of potential issues.
In conclusion, the thermal runaway of lithium batteries presents a major challenge that requires innovative solutions. By exploring the internal chemical reactions, understanding the trigger sequence, and suggesting a gas-based early warning strategy, researchers can pave the way for safer and more reliable lithium battery applications. As technology continues to advance, these insights will be crucial in ensuring the continued growth and sustainability of industries relying on lithium batteries.