TU-TESL

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(source: RPI official website) nowadays, most mobile phones, laptops and electric vehicles are powered by lithium ion. With the charging speed becoming faster and faster, the performance requirements are higher and higher, and the price of these batteries is more and more expensive, and more flammable. According to foreign media reports, engineers at Rensselaer Polytechnic Institute in the United States use aqueous electrolyte to produce batteries. Compared with the traditional organic electrolyte, the new battery is safer, more cost-effective and has better performance. Inside the battery, the positive and negative electrodes are immersed in a liquid electrolyte. When the battery is charged and discharged, the liquid electrolyte will conduct ions. Aqueous electrolytes are of great concern due to their nonflammability. In addition, in the manufacturing process, unlike non-aqueous electrolytes, aqueous electrolytes are not easily affected by water, more convenient to operate and lower cost. The biggest challenge for this material is how to maintain performance. "If you apply too much voltage to an aqueous solution, it will electrolyze and break down into hydrogen and oxygen." "Normally, the voltage window of this material is very limited," said Nikhil koratkar, Professor of mechanical, aerospace and nuclear engineering at rensler In this study, koratkar and his team used a special aqueous electrolyte, water in salt electrolyte, which is not easy to electrolyze. At the same time, the researchers used lithium manganese oxide as the positive electrode and niobium tungsten oxide as the negative electrode. According to koratkar, niobium tungsten oxide is a kind of complex oxide, which has never been found in water battery before. "It has been proved that the energy storage per unit volume of niobium tungsten oxide is outstanding. In terms of volume, it is the best water lithium-ion battery so far. " According to reports, the weight and density of niobium tungsten oxide are relatively large, so the energy storage capacity based on mass is close to the average level; due to the dense accumulation of niobium tungsten particles in the electrode, the energy storage capacity based on volume is quite high. The crystal structure of this material provides a channel for lithium ion to spread rapidly, so it can be charged quickly. Koratkar said the new battery charges fast and has a large capacity per unit volume, which is rare in water batteries. For emerging applications, such as portable electronic devices, electric vehicles and grid storage, it is crucial to store as much energy as possible in a limited volume.