Battery additives are a class of functional additives that enhance battery performance. Battery additives have an important impact on the safety, cycle life, electric capacity and other properties of the battery, and are an indispensable component of the battery. For secondary batteries, battery additives are classified into electrode additives and electrolyte additives. Different additives have different functions. These battery additives can enhance the stability and conductivity of the electrode, prolong the life of the battery, prevent the deterioration of the electrolyte, and enhance the electric capacity of the battery, and are widely used in the battery field.
Figure 1. Simple classification of battery additives
- Anode additives: Adding appropriate additives to the anode active material can improve the conductivity, porosity and bonding force between the positive electrode material particles, thereby inhibiting the corrosion of the electrode material, improving the utilization rate of the active material or prolonging its life.For example, in lead-acid batteries, the use of conductive materials as additives in the positive lead paste can improve the utilization rate of positive active materials.
- Cathode additives: Cathode additives are mainly used to improve battery life and the overall performance of the negative plate, and can be divided into inorganic additives and organic additives. Inorganic materials mainly include barium sulfate, strontium sulfate, carbon black, etc. These additives can be highly dispersed in the active material to keep the electrode active material highly active. The variety of organic additives is very rich, which can also improve the activity of active substances.
- Electrolyte additives: According to the function of additives, additives in electrolyte can be divided into film-forming additives, conductive additives, flame retardant additives, overcharge protection additives, multifunctional additives, etc. The addition of these additives affects the composition and electrochemical performance of the electrolyte. Conductive additives can increase the conductivity of the electrolyte. Flame retardant additives can enhance the safety of battery use and prevent spontaneous combustion or explosion caused by improper use. Overcharge protection additives can prevent the decomposition or denaturation of the electrolyte under the condition of overcharge, and prevent the capacity loss of the battery. Many current electrolyte additives are organic compounds, which have the advantages of diverse properties and rich structures, and can meet various needs of battery performance.
- Katsuhiko Tsunashima, Fumihiro Yonekawa, Masahiro Kikuchi, Masashi Sugiya. Tributylmethylphosphonium Bis(trifluoromethylsulfonyl)amide as an Effective Electrolyte Additive for Lithium Secondary Batteries [J]. J. Electrochem. Soc., 2010, 157, A1274.