02 Sep High Performance Phenylcyclohexane Produced by Zhongneng Chemistry is Widely Used in Lithium Battery Industry
Phenylcyclohexane is an important chemical intermediate that has high boiling point and freezing point which is close to ambient temperature. Phenylcyclohexane is mainly produced by combining benzene with cyclohexene, cyclohexanol and halogenated cyclohexane. The synthetic technique was immature in the past and phenylcyclohexane could only be produced in small scale due to the poor selectivity, nonreusable and environmental pollution of catalysts. Jiangsu Zhongneng Chemistry has developed a new, high content and environmental manufacturing technique of high purity phenylcyclohexane, and the product is widely used in industries of liquid crystal, organic synthesis, high boiling point solvent and lithium battery.
In lithium battery industry, phenylcyclohexane is mainly used as the lithium-ion battery electrolyte additive, preventing battery from overcharging and improving battery security. As the overcharge protection additive, phenylcyclohexane should have following properties. First, it should have good solubility and fast diffusion velocity in organic electrolyte to provide protection in large current range. Second, it should have strong stability in battery operating temperature range. Third, it should have appropriate oxidation potential. Fourth, there is no side reaction of oxidative product in reduction process. Fifth, additives should have no side effect.
There are two explanations about phenylcyclohexane overcharge protection mechanism. 1. Self-discharge mechanism: Electropolymerization of additive monomer occurs to generate conducting polymer film on anode surface when battery charging reaches a certain voltage, which makes battery self-discharge to secure state. 2. Block mechanism: When battery voltage exceeds additive electropolymerization voltage, polymerization reaction of additive monomer occurs to generate dark phenylcyclohexane that forms blocking layer on electrode surface and increases battery internal resistance, which decreases or stops electrolyte further decomposition and significantly reduces generated gas and heat, avoiding thermal runaway and keeping battery at safe state.
Phenylcyclohexane additive has no effect on battery initial discharge capacity, but high additive amount adversely affects battery cycle performance. Proper proportion of additive can guarantee cycle performance and service life of battery. Based on research results, when the content of phenylcyclohexane in electrolyte is about 5%～7% (mass ratio), the effect is optimum. When additive content is less than 5%, the overcharge protection effect is unclear. When additive content is over 7%, electrolyte conductivity decreases, battery cycle performance reduces and self-discharge level increases. Reasonable control of phenylcyclohexane content in electrolyte can guarantee the optimum overcharge protection effect in lithium battery industry.
Jiangsu Zhongneng Chemistry Co. Ltd., as the leader of functional chemistry enterprise, has experienced a series of technical innovations and broken through the difficulty of separation and purification of phenylcyclohexane and its by-product. The purity of our phenylcyclohexane is ≥99.95%, satisfying requirements of high end users. Our superior DYNOVA® phenylcyclohexane is the ideal additive in lithium battery industry and Jiangsu Zhongneng Chemistry is your trustworthy business partner.