Ten Insights on Electrolytes - I

   The electrolyte is a crucial component of lithium batteries, serving to conduct lithium ions within the battery and significantly influencing its performance and lifespan. Lithium battery electrolytes typically consist of organic solvents, electrolytes, and additives.

  Based on the physical properties of solvents, electrolytes can be classified into liquid electrolytes, solid electrolytes, and molten salt electrolytes. Liquid electrolytes are mainly used in cylindrical and prismatic lithium batteries, while solid electrolytes are primarily applied in pouch batteries. Solid electrolytes are a new type of electrolyte, with higher costs than liquid electrolytes; currently, liquid electrolytes are the most widely used.

  Liquid electrolytes can be further divided into organic liquid electrolytes, inorganic liquid electrolytes, and ionic liquid electrolytes, depending on their liquid properties. Solid electrolytes can be categorized into inorganic solid electrolytes and polymer solid electrolytes. Polymer solid electrolytes offer advantages such as light weight, pressure resistance, shock resistance, non-toxicity, non-corrosiveness, and high electrochemical stability, leading to broader applications. They can be further divided into all-solid-state polymer electrolytes and gel polymer electrolytes. Molten salt electrolytes involve melting metal salts through electrical energy; however, due to their strong corrosiveness and radioactivity, they are not widely used.

  Organic solvents are the main components of electrolytes and are typically flammable, explosive, and toxic liquids, such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC). These organic solvents can dissolve electrolytes to form ionic conductors while also providing a certain degree of electrochemical stability.

  The electrolyte is the ionic conductor within the electrolyte solution, typically a lithium salt such as LiPF6, LiBF4, or LiClO4. These lithium salts can dissociate into lithium ions and negative ions in the electrolyte, enabling lithium ion conduction.