What are the aging mechanisms of lithium ion batteries?

The primary aging mechanisms of LIBs include the formation and growth of Solid Electrolyte Interface (SEI), the deposition of metallic lithium at the anode, mechanical fracture of electrode materials, and the consumption of electrolytes and additives, etc.

How do lithium ions move in a battery?

During the charge and discharge of the battery, lithium ions at the positive and negative electrodes gradually diffuse out of the crystal lattice of the electrode material. Lithium ions mainly move through diffusion in the solid-phase particles inside the battery.

How does a lithium battery work?

2.1.2. Battery operating principle During the initial charging process, lithium ions move from the cathode material through the separator and intercalate into the graphite layers of the anode. Simultaneously, lithium bonds on the graphite surface to form a SEI.

What is the function of a sei in a lithium ion battery?

In addition to cathode stability, the stability of the anode material plays a crucial role in the safe operations of the battery. The primary function of the SEI is to protect the anode and the active Li from contact with the electrolyte and avoid unnecessary side reactions.

How do rechargeable lithium-ion batteries work?

Rechargeable lithium-ion batteries of today operate by an electrochemical process that involves intercalation reactions that warrants the use of electrode materials having very specific structures and properties. Further, they are limited to the insertion of one Li per 3D metal.

How does a lithium ion battery react with a cathode?

At elevated temperatures, oxygen released from the cathode can react intensely with the electrolyte or anode, drastically raising the battery's temperature. The greater the amount of lithium retained in the anode (the higher the SOC), the greater the energy release upon reaction, and, consequently, the higher the risk of thermal runaway.