This paper centers on a design strategy that integrates both ion transport and passivation properties within the electrolyte. It elucidates how the solvation sheath and solvation dynamics of lithium ions influence film‑forming behavior and lithium‑ion transport, and develops an electrolyte system using fluoroethylene carbonate (FEC) and acetonitrile (AN) as solvents and lithium hexafluorophosphate (LiPF6) as the lithium salt. By engineering a solvation structure in which FEC‑dominant coordination ligands are embedded in an AN‑rich environment, the approach effectively addresses the bottlenecks associated with fast‑charging electrolytes. Furthermore, by assembling pouch cells, the study explores the commercial viability of the proposed electrolyte.

He went on to explain that hydrogen sits above lithium and is used in fuel cells, while sodium lies below lithium and powers sodium-ion batteries, which require sodium hexafluorophosphate. With these three high‑energy elements at the top left of the periodic table, and under the influence of fluorine, a global new‑energy system has taken shape.

New technologies and products are being rapidly commercialized, driving the company’s long-term growth. In the sodium hexafluorophosphate segment, leveraging its existing lithium hexafluorophosphate synthesis expertise, the company has developed proprietary processes for producing both concentrated and solid forms of sodium hexafluorophosphate and has now entered the pilot‑scale production phase. For NaFSI, building on its in‑house LiFSI technology, the company has established corresponding sodium‑salt synthesis routes and has also pioneered a high‑purity sodium fluoride synthesis process, helping to ensure stable raw‑material supply and consistent product quality. In the 46‑series large cylindrical battery segment, the company has completed optimization of the solvent system, validated novel lithium salts as alternatives to hexafluorophosphate, and verified conventional additives, thereby providing an effective electrolyte solution for next‑generation large cylindrical cells such as the 4680.

The void volume between the positive and negative electrodes, as well as the electrode porosity, is filled with the electrolyte. The electrolyte is a solution of a lithium salt in an organic solvent mixture. In commercial batteries, lithium hexafluorophosphate (LiPF6) is used as the lithium salt.

Electrolytes are typically formulated by blending high-purity organic solvents, lithium salt electrolytes (such as lithium hexafluorophosphate, LiPF6), and essential additives, under specific conditions and in precise proportions. Lithium salts serve as the primary carriers of lithium ions, while organic solvents act as the medium for dissolving, dispersing, and supporting these salts. Additives primarily function to enhance the electrochemical performance and overall functionality of lithium‑ion batteries.

Currently, lithium hexafluorophosphate is the most widely used lithium salt in electrolytes, owing to its stable overall performance and controllable cost. However, it still has certain drawbacks: poor thermal stability, HF‑producing decomposition products that degrade high‑temperature battery performance, and low ionic conductivity at subzero temperatures. To address these limitations, lithium bis(fluorosulfonyl)imide (LIFSI), which offers superior thermal stability and excellent performance across a broad temperature range, has been employed to enhance the electrolyte’s overall characteristics. Previously, its limited adoption was attributed to its strong corrosivity and high price. Regarding aluminum‑foil corrosion, this issue can now be mitigated by using alternative additives to promote early passivation of the foil. Meanwhile, with the sustained price increase of lithium hexafluorophosphate, LIFSI has become relatively more attractive, prompting battery manufacturers to gradually explore higher loading levels.