How to prevent and control the safety risks of lithium battery production?

First, prevention and control of poisoning risks in the production and use of fluorine-containing electrolytes. The biggest risk of using phosphorus pentafluoride and hydrogen fluoride in the manufacture of lithium potassium hexafluoride is the risk of hydrogen fluoride poisoning,best lithium ion battery machine company while during the preparation of electrolyte, the dangers related to the poisoning of lithium potassium hexafluoride should be prevented and controlled.

At present, some of the domestic lithium hexafluorophosphate production enterprises are not high level of intrinsic safety, the box-type fluoridation reactor has not yet realized automatic control,equipment for lithium battery assembly the use of artificial charging, and even hydrogen fluoride venting tail gas and other process piping are made of plastic, which is far from the automatic control of the fluoridation process requirements, let alone the automatic control of upstream and downstream. In addition, some enterprises have weak awareness of the risk of hydrogen fluoride poisoning.

In this case, the first thing to do is to strengthen the risk awareness. In particular, enterprises producing and using fluorine-containing electrolytes involving the use of hydrogen fluoride, which have developed rapidly in recent years, should strengthen the training of preventing and controlling the risk of hydrogen fluoride poisoning. Secondly, it is necessary to strengthen the management of equipment integrity and prevent and control equipment corrosion and leakage. Starting from the design stage of equipment and material selection, we should consider the characteristics of the fluorine chemical process, the role of material damage to the material under different process conditions; the use of various types of micro-leakage detection tools (eg: infrared thermography, industrial acoustic imaging, etc.), leakage of the early discovery, early treatment.

Second, to prevent and control the risk of lithium perchlorate explosion. Lithium perchlorate is a common electrolyte, belonging to perchlorate. It is a colorless or white crystalline powder. Lithium perchlorate begins to decompose at around 400 °C and immediately decomposes at 430 °C, producing lithium chloride and oxygen, which is the highest oxygen mass fraction and volume fraction of perchlorate except for the expensive and highly toxic beryllium perchlorate. Due to its high oxygen content, it can be mixed with reductants, organics, sulfur, phosphorus, metal powders and other flammable substances to form explosive mixtures, which are prone to decompose and explode under the effect of external impact, explosion and shock.

Therefore, the operation process of lithium perchlorate requires airtight operation to avoid the release of dust into the air, avoid contact with oxidizing agents, acids and carbon dioxide, and avoid collision and knocking.

Research shows that due to the poor low-temperature performance and explosion risk of lithium perchlorate batteries, Japan and the United States have banned the use of such batteries. Domestic relevant research institutions and enterprises should pay great attention to the explosion risk of lithium perchlorate.

Third, prevent and control the flash explosion and fire risk of high-purity solvents. The high-purity solvents used in the electrolyte mainly include ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC) and other carbonate esters, of which the flash point of methyl ethyl carbonate, dimethyl carbonate, diethyl carbonate are 23 ℃, 19 ℃, 25 ℃, respectively, as a class A substance; ethylene carbonate, propylene carbonate flash point 150℃, 123℃ respectively. Among them, dimethyl carbonate, diethyl carbonate is a flammable liquid, in case of open flame, high heat or contact with oxidizing agent, there is a danger of causing combustion and explosion.

First of all, we should prevent and control the risks in the preparation and use of high-purity organic solvents. First, when adding material to the preparation kettle, attention should be paid to the feeding and stirring speed to prevent excessive speed and static spark ignition and explosion. Change the upper feeding tube to lower feeding tube to avoid violent stirring when feeding. Second, the preparation kettle in the operation process, prohibit the use of mechanical equipment and tools easy to produce sparks, are not allowed to knock or impact equipment, otherwise it will be due to the generation of knocking, impact sparks and fire and explosion accidents. Third, strict control of the production process in the workshop may appear in a variety of ignition sources, the use of explosion-proof electrical equipment. When opening vats containing materials and semi-finished products, the use of iron tools is strictly prohibited.

Secondly, it is necessary to prevent and control the risks in the production and synthesis of high-purity organic solvents. At present, there are five main production processes for carbonate solvents that are widely used in electrolyte, namely, phosgene method, methanol oxidation carbonylation method, ester exchange method, urea alcoholysis method, carbon dioxide direct oxidation method, etc.. Among them, the phosgene method has been phased out due to the high toxicity of phosgene, serious pollution of "three wastes" and poor product quality, and the main domestic non-phosgene method. In the main domestic production process, ethylene oxide is involved in the production of vinyl carbonate, propylene carbonate involves propylene oxide in the production process, dimethyl carbonate, diethyl carbonate can be prepared by propylene carbonate method, and methyl ethyl carbonate can be prepared by dimethyl carbonate.

The preparation process of solvents is complex, although it does not involve hazardous chemicals, but it involves dangerous chemicals, the separation and distillation operation unit is complex, the whole process is risky, the lack of corresponding standards and norms, enterprises must pay attention to. Enterprises should be based on risk, based on HAZOP, LOPA analysis, equipped with the necessary automated control systems and safety instrumentation systems.