Thursday, 26 February 2015

The new lithium battery electrolyte substantially increase the efficiency and service life

US Department of Energy scientists at Pacific Northwest National Laboratory have developed a new type of electrolyte, lithium-ion batteries can not only solve the problem of short circuit fire, but also a substantial increase in battery performance and life. The researchers said the discovery could lead to the next generation of more powerful and practical rechargeable batteries, such as lithium sulfur and lithium-air and lithium metal batteries.

US Department of Energy scientists at Pacific Northwest National Laboratory have developed a new type of electrolyte, lithium-ion batteries can not only solve the problem of short circuit fire, but also a substantial increase in battery performance and life. The researchers said the discovery could lead to the next generation of more powerful and practical rechargeable batteries, such as lithium sulfur and lithium-air and lithium metal batteries.
Most rechargeable batteries are lithium ion batteries, lithium or other anode materials, cathode is usually made of graphite. When the battery is connected, the electrons flow between the poles will generate electricity. In order to control electronics, lithium-ion with a positive charge will be via the electrolyte from pole to pole. But the low storage capacity of graphite, which limits the capacity of the lithium-ion battery. So during the 1970s, people developed a lithium-based rechargeable battery cathodes. Chose lithium than graphite because it has more than 10 times more storage capacity. But the problem is that this will lead to dendritic growth of lithium dendrites on the microscopic appearance, so that the battery short-circuit faults. Over the years many people have tried to solve this problem.
There scientists are using a protective coating the anode material, and some others produced the electrolyte additives. Some solutions indeed eliminate dendrites, but also led to a significant reduction in battery power and electricity. There are other solutions to this phenomenon can only slow down, but can not let dendrites stop growing.
Yesterday the media reported that the US Department of Energy by the Pacific Northwest National Laboratory developed a new type of electrolyte which not only the perfect solution dendritic problem, but also help to play 99% of the lithium-ion battery performance, the energy density per unit area increased by 10 times.
Responsible for the study of the Pacific Northwest National Laboratory physicist Zhang Jiguang (transliteration) said today widely used in rechargeable lithium-ion battery capacity is approaching its peak, should be to lithium as the anode design re-examined. Based on previous research, Zhang Jiguang and his colleagues decided to use lithium imide salt contains a large double (sulfuryl fluoride) as a new type of battery electrolyte. In addition, they also added a substance is known dimethoxyethane.
Researchers created a circular test cell. Using the new electrolyte and a lithium anode in a battery. It was found that only the presence of a lithium anode produced some smooth lithium node without a large number of fibrous dendrites. After 1000 charge-discharge cycles, the test battery power is still the initial value of 98.4%, the energy density was maintained at 4 mA per square centimeter.
This new electrolyte is very efficient, but also provides a new possibility. Today cell cathode consists essentially of graphite coated with a thin metal sheet or the like of the active material of lithium made. The metal foil is known as the collector, because our mobile phones and other electrical appliances is to obtain the current through it. The need for coating the active material in the above, because by far the majority of the electrolyte during the battery operation will consume lithium ions. However, over 99% of the efficiency of the electrolyte means that only the possibility of creating a negative current collector and the active material is not coated cathode. This is expected to significantly reduce production costs and battery size, it will significantly improve the safety of these batteries.
Researchers are evaluating various additives to further improve the performance of the electrolyte, the lithium ion battery reaches 99.9% efficiency.

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