What role does lithium hexafluorophosphate play in the electrolyte?

It is the most common lithium salt in liquid lithium-ion battery electrolytes. Dissolved in a blended carbonate solvent, it dissociates into lithium ions that carry charge between the electrodes. Ionic conductivity and current-collector compatibility depend heavily on the salt.

How are electrolytes typically formulated?

A widely cited baseline in open literature is roughly 1 mol/L lithium salt in a mixed carbonate solvent such as ethylene carbonate (EC) and ethyl-methyl carbonate (EMC), with small amounts of film-forming or flame-retardant additives. The exact solvent ratio is tuned per cell chemistry (power, storage, low-temperature) and is not a single fixed recipe.

What should be considered for storage and transport?

Lithium hexafluorophosphate is sensitive to moisture and oxygen; on exposure to water it can decompose and release HF. It should be sealed, kept dry, and handled under inert atmosphere where possible, with transport carried out per hazardous-chemical regulations. On receipt, verify the batch COA and consider third-party retesting for critical lots.

Electrolyte Is Central to Long-Range EV Batteries: A Sourcing View of LiPF6 and Co-Solvents

2026-09-26 · Keyword：Lithium hexafluorophosphate · CAS 21324-40-3 · Jinan Shenghe Chemical Co., Ltd. · 中文

Long-range electric vehicles keep making headlines — a recent model pushed pure-electric range toward the 1100 km mark. Beyond the marketing, how far a battery goes is a materials-engineering story. The electrolyte is often overlooked, yet it decides how efficiently and stably lithium ions shuttle between the electrodes. This article looks at the core lithium salt and its co-solvents from a sourcing and quality-control perspective.

The lithium hexafluorophosphate (CAS 21324-40-3) and the co-solvents mentioned below are all listed in our product catalog: lithium hexafluorophosphate, carbonate solvents.

1. Basic specifications

Name	Lithium hexafluorophosphate
CAS	21324-40-3
Formula	LiPF₆
Molecular weight	151.98 g/mol
Melting point	~200 ℃ (near decomposition)
Category	New Energy Materials
Spec / packaging	Per batch COA; confirmed per order

Figures above are published physical properties; actual values follow the batch COA and order confirmation.

2. Why electrolytes rely on LiPF6

Among the lithium salts discussed most often — LiPF₆, LiBF₄, LiTFSI — LiPF₆ is the most widely used because it balances ionic conductivity, aluminum-current-collector passivation, and cost. It forms a stable passivation layer on aluminum, preventing corrosion at higher voltages, while dissolved lithium ions conduct well enough for everyday charge/discharge. Its weakness is real too: moisture sensitivity and thermal decomposition, which is exactly why downstream buyers control water and free acid tightly.

3. Co-solvents are not "fillers"

Ethylene carbonate (EC, CAS 96-49-1): high dielectric constant, excellent at dissociating the salt and enabling the solid-electrolyte interphase, but viscous and poor at low temperature alone.
Propylene carbonate (PC, CAS 108-32-7): wide liquid range and good low-temperature behavior, often used to broaden the operating window, though it needs film-forming additives on graphite anodes.
Ethyl-methyl carbonate (EMC, CAS 623-53-0): low viscosity, improves low-temperature and rate performance, commonly used to dilute EC/PC.

A typical open-literature baseline is "about 1 mol/L LiPF₆ in EC:EMC ≈ 3:7 with a little PC or functional additive." This is illustrative only; real formulations are each cell maker's core know-how, tuned against cathode chemistry, energy-density targets, and safety margins.

4. Sourcing and QC checkpoints

Water (H₂O): kept very low (often single-digit to ~20 ppm in industry); high water accelerates LiPF₆ hydrolysis to HF.
Free acid (as HF): an upper limit is enforced to avoid electrode corrosion.
Metals and insolubles: affect yield and electrical performance.

Moisture-proof sealed packaging, sometimes inert atmosphere, and transport per hazardous-chemical regulations are standard. Beyond the supplier COA, retain samples and run third-party checks on critical lots so incoming inspection becomes routine rather than occasional.

5. Explain the use case when selecting

The same LiPF₆ electrolyte behaves very differently in power, stationary storage, or low-temperature cells. Share the application, target temperature range, and matched cathode chemistry when requesting a quote, so the supplier can advise a realistic specification instead of quoting a generic "standard grade."

FAQ

What role does lithium hexafluorophosphate play in the electrolyte?: It is the most common lithium salt in liquid lithium-ion battery electrolytes. Dissolved in a blended carbonate solvent, it dissociates into lithium ions that carry charge between the electrodes. Ionic conductivity and current-collector compatibility depend heavily on the salt.
How are electrolytes typically formulated?: A widely cited baseline in open literature is roughly 1 mol/L lithium salt in a mixed carbonate solvent such as ethylene carbonate (EC) and ethyl-methyl carbonate (EMC), with small amounts of film-forming or flame-retardant additives. The exact solvent ratio is tuned per cell chemistry (power, storage, low-temperature) and is not a single fixed recipe.
What should be considered for storage and transport?: Lithium hexafluorophosphate is sensitive to moisture and oxygen; on exposure to water it can decompose and release HF. It should be sealed, kept dry, and handled under inert atmosphere where possible, with transport carried out per hazardous-chemical regulations. On receipt, verify the batch COA and consider third-party retesting for critical lots.

Note: This page is for industrial raw-material technical discussion only. Products are supplied for industrial and research use, not for consumer or medical use. Specifications, compliance documents and transport requirements follow the batch COA and order confirmation.