Synthesis of LiPF₆ Using CaF₂ as the Fluorinating Agent Directly: An Advanced Industrial Production Process Fully Harmonious to the Environments

Abstract

A novel method to synthesize the important lithium-ion battery electrolyte LiPF6 was developed and successfully applied in industrial-level production. In comparison with the conventional synthetic routes, the method employed CaF2 as the direct fluorinating agent instead of the corrosive and toxic HF. It was suitable for the surrounding environments of our company: the nearby fluorite mine could provide CaF2 at a relatively lower price, while the generated CaCl2 byproduct could be sold as the snowmelt agent for the surrounding highways, avoiding the accumulation of the solid wastes. Moreover, the product quality was obviously enhanced owing to the unique HF-free processes, which were environment-friendly and could even be performed near the national natural reserve. This work should be a good example of sustainable chemistry showing that the chemical industry could also be fully harmonious to the environments owing to the advanced green techniques.

Graphite Recycling from the Spent Lithium-Ion Batteries by Sulfuric Acid Curing–Leaching Combined with High-Temperature Calcination

“…Traditionally, the waste anode materials are discarded to an open land. If these dangerous wastes are not disposed properly, they will evidently threaten the ecological environment and human health. − On the other hand, if the spent graphite (SG) can be recycled and reused in the LIBs, the shortage of graphite resources will be alleviated and also the sustainable development of a new energy industry can be facilitated. − …”

Ton-Scale Production of 1,4-Bis(dichloromethyl)-2,5-dichlorobenzene via Unexpected Controllable Chlorination of 1,4-Dichloro-2,5-dimethylbenzene

“…To resolve the poor selectivity issue of the chlorization reaction, a series of chlorination reagents have been developed to improve the reaction selectivity, such as SO 2 Cl 2 , NaOCl, t- BuOCl, Et 4 NCl, trichloroisocyanuric acid (TCCA), etc. − However, despite their expensive prices and the inavoidable generation of solid wastes after the reaction, many of the reagents are toxic, explosive, and corrosive and none of them can be employed in the chlorination of 1 to produce 2 up to the present. We have paid continuous attention to green chemical transformations with high atom utilization ratios − and aim at developing related catalysts , and efficient synthetic methods , with industrial application potential. Recently, the synthesis of 2 came into our sight for the significant applications of the chemical in herbicide production.…”

“…6−12 However, despite their expensive prices and the inavoidable generation of solid wastes after the reaction, many of the reagents are toxic, explosive, and corrosive and none of them can be employed in the chlorination of 1 to produce 2 up to the present. We have paid continuous attention to green chemical transformations with high atom utilization ratios 13−15 and aim at developing related catalysts 16,17 and efficient synthetic methods 18,19 with industrial application potential.…”

Fluorochemicals from fluorspar via a phosphate-enabled mechanochemical process that bypasses HF

“…To date, limited chemistry is known for the production of fluorochemicals using CaF 2 . Rare examples report its use in the synthesis of LiPF 6 , PF 5 , POF 3 , or Ca(SO 3 F) 2 under extremely harsh conditions ( 10 – 12 ). Synthetic porous CaF 2 obtained from soda lime and HF was reported for the conversion of α-chloro ethers to α-fluoro ethers at 200°C ( 13 ).…”