Researchers have developed a new electrolyte to improve the performance of lithium-ion batteries

Core tip: Researchers at the American Chemical Society have previously said they can replace some vinyl carbonates with propylene carbonate and add hexafluorophosphate to expand the operating temperature range of lithium-ion batteries. But the researchers hope to further expand the temperature range so that lithium-ion batteries can operate at minus 40 to 60 degrees Celsius.

According to foreign media reports, electric vehicles are affected by temperature changes, mainly because the electrolyte of their lithium-ion batteries is susceptible to temperature. Now, researchers have developed a new electrolyte that contains a variety of additives that can make lithium-ion batteries perform better over a wider range of temperatures.

Lithium-ion batteries are widely used in mobile phones, laptops, and electric vehicles, where the electrolyte solution in the battery conducts ions between the positive and negative electrodes of the battery to power the battery. An essential ingredient in this solution is the vinyl carbonate group, which helps to form a protective layer that prevents the electrolyte components from further decomposing when they come into contact with the anode. However, polycarbonate has a high melting point, which limits its performance at low temperatures.

Previously, researchers from the American Chemical Society have demonstrated that it can replace some vinyl carbonates with propylene carbonate and add hexafluorophosphate to extend the operating temperature range of lithium-ion batteries. But the researchers hope to further expand the temperature range so that lithium-ion batteries can operate at minus 40 to 60 degrees Celsius.

The researchers tested the effects of five electrolyte additives on lithium-ion battery performance over this temperature range, determining the optimal combination of three compounds added to the previous electrolyte solution that formed a protective layer of high conductivity, uniformity, and robustness at the anode and cathode. Batteries containing an optimized electrolyte showed improved discharge performance at -40C, a significant improvement in cycling stability at 25C, and a slight improvement in cycling stability at 60C.