4-Nitrobenzoic acid (p-nitrobenzoic acid) is an organic compound with the chemical formula C7H5NO4. It can be used in battery materials as an electrolyte additive, conductive material additive, lithium-ion battery cathode material additive, and electrolyte additive.
1. As an Electrolyte Additive
p-nitrobenzoic acidplays a role in electrolytes primarily through chemical adsorption and ion solvation. During battery operation, ions need to dissociate from the electrode and transport through the electrolyte. However, during this transport, ions often become solvated by solvent molecules, forming solvated ions. Solvated ions can affect the transport efficiency and diffusion rate of the ions, thus impacting battery performance. 4-Nitrobenzoic acid can coordinate with ions, reducing their degree of solvation, thereby improving the ionic conductivity and stability of the electrolyte. Additionally, 4-nitrobenzoic acid can chemically adsorb to reduce side reactions in the electrolyte, enhancing the battery's cycle life and capacity retention rate.
2. As a Conductive Material Additive
p-nitrobenzoic acid can form hydrogen bonds or π-π stacking interactions with conductive materials like carbon nanotubes and polymers, increasing the charge transport efficiency and electrical conductivity of the conductive material. Specifically, the carboxyl and nitro groups in 4-nitrobenzoic acid molecules can chemically react with functional groups in carbon nanotubes and polymers, forming hydrogen bonds or π-π stacking interactions, thereby enhancing the rate of electron transport and electrical conductivity. Moreover, the chemical structure of 4-nitrobenzoic acid can influence the charge distribution and spatial structure on the surface of the conductive material, further improving the conductive performance.
3. As a Lithium-Ion Battery Cathode Material Additive
p-nitrobenzoic acid can be added to lithium-ion battery cathode materials, such as lithium iron phosphate (LiFePO4), to increase the specific surface area, conductivity, and stability. The principle is that the transport of lithium ions within the cathode material requires passage through many interfaces, which are related to the surface area of the cathode material. Therefore, increasing the surface area of the cathode material can improve the transport efficiency of lithium ions within the cathode material. 4-Nitrobenzoic acid can form coordination bonds with lithium ions, enhancing the lithium ion conductivity and ion transport efficiency of the cathode material, while reducing the generation of side reactions in the battery, thus improving the cycle life and capacity retention rate of the battery. Additionally, the carboxyl group in 4-nitrobenzoic acid can chemically react with hydroxide ions on the surface of the cathode material to form a protective film, reducing the interaction between the cathode material and the electrolyte, thereby improving the stability and durability of the battery.