The widespread use of lithium ion batteries in portable electronic devices such as laptops, mobile phones and so forth has made our daily lives extremely convenient, but the safety of these batteries has been a constant concern for many. Recently, a study from the united states indicated that a special “saline water” is expected to improve the safety of lithium ion batteries。
Lithium ion batteries sometimes have safety problems such as explosions because they usually use flammable organic solvents as electrolytes. The use of aqueous solutions in lieu of organic solvents not only significantly reduces the flammability of electrolyte but is also more environmentally friendly. One difficult problem, however, is that under the normal working voltage of lithium ion cells, water is easily electrolytic to hydrogen and oxygen, which makes batteries more dangerous and even very small amounts of hydrogen can seriously affect their performance。
A research team led by two chinese scholars from the university of maryland in the united states, professor wang chunsheng, and dr. Xu kang, the united states army research laboratory, tried new ideas. They dissolved a lithium ion compound, trifluoromethane lithium in water at very high concentrations, resulting in a unique “saline water”. Since the volume and mass of lithium salt in the solution are higher than the water, this “saline water” should actually be considered as a solution formed by water solubility in lithium salt. The conductivity of the solution is comparable to the electrolyte of the conventional organic solvent, which is significantly less flammable. During battery use, lithium salt in the solution is electrolytic before water, and electrolyte products are deposited on the electrode to form a protective layer to prevent electrolysis of the water without disruption to the conductive capacity. Similar protection layers are common in batteries that use non-hydroelectric decomposition, but because hydrolyte-based electrolyte products are hydrogen gas and oxygen, it is often difficult to form solid-state protection layers, and this new study has skilfully addressed the problem。
Further experiments have shown that lithium ion batteries constructed using this new electrolyte perform well. Thus, the safety of lithium ion batteries is expected to improve significantly in this way。
Compiled: embedded co-promote
