1. Features and parameters (Feature)

Indicator: parameter value

Chemical formula: LiAsF₆

CAS number: 29935-35-1

Appearance: white crystalline powder

Purity: ≥99.9% (ICP-MS detection)

Water content: ≤10ppm (Karl Fischer method)

Particle size distribution: (D50) 5-20μm (customizable micron level)

2. Advantage & Benefit

Core application scenarios:

Lithium-ion battery electrolyte: used in conjunction with LiPF₆ to improve the cycle stability of high-voltage positive electrodes above 4.5V (such as NCM811), extending the life by 30%+

Solid electrolyte additives: reduce interface impedance and enhance ion conductivity (0.1-1 mS/cm, 25℃)

Supercapacitors: improve electrolyte oxidation resistance and support operating voltages above 3.5V

Uses

The surface chemistry of lithium electrodes in etherified LiAsF6 has been tested with novel salts and is expected to be used in battery systems.

Production method

Place about 8 kg of hexafluoroarsenic acid in a polyethylene container and add filtered 5 mol/L LiOH solution to neutralize it to a pH of about 8 to 10. Keep it at 100°C for several hours, then filter to remove solid byproducts (mainly LiF and lithium hydrogen arsenate, about 1.4 kg). The solution is concentrated by rotary evaporation at 55 to 60°C, then adjusted to pH=8, and filtered to remove insoluble byproducts (about 10 to 15 g). Filter with a polyethylene funnel to obtain LiAsF6·3H2O, dissolve it in water again at 65 to 70°C according to 1.5 to 2.0 mL water/100 g, and separate the product after cooling. Then dissolve it in water at 25°C, adjust the pH to about 8, concentrate and filter while hot. Recrystallize it twice with 7.5×10-4 mol/L LiOH aqueous solution. Finally, 2838 g of LiAsF6·3H2O crystals are obtained. The mixture was freeze-dried for several days under a vacuum of 0.133 Pa and then heated to 40° to obtain 2136 g of anhydrous LiAsF6.

Team Presentation