Recently, Zhejiang University Department of Polymer Science and Engineering team developed a new aluminum - graphene battery. This battery can be minus 40 degrees Celsius to 120 degrees Celsius environment can be described as both high temperature and anti-freezing. 30 degrees Celsius environment, this new battery can achieve 1,000 charge and discharge performance diminished, and in the 100 degrees Celsius environment, it can achieve 4.5 million cycles of stability.
The new battery is flexible and retains its full capacity after it is bent 10,000 times, and it does not catch fire or explode even when it is exposed to flames.
December 15, Related papers Ultrafast all-climate aluminum-graphene battery with quarter-million cycle life Posted in Science Advances, the first author of the team Dr. Chen Hao.
The battery does not burn at high temperatures
Heat-resistant, freeze-resistant and kink resistant 'longevity' batteries
A piece of metallic luster of the dark gray film, is the team newly developed graphene - aluminum battery. Its positive electrode is a graphene film, the negative electrode is aluminum. The two batteries connected in series, you can light a group of LED Lamp has been tested, graphene positive electrode capacity of 120mAh / g (mAh per gram), after 250,000 charge and discharge cycles can still maintain the capacity of 91% at the same time its rate performance, fast charging 1.1 seconds Fully charged, still has a reversible capacity of 111mAh / g.
The aluminum-graphene battery lit up the LED string printed with 'ZJU120'
Compared to lithium batteries, advanced research team developed aluminum - graphene battery shows obvious advantages: With repeated charge and discharge of the battery, the specific capacitance will continue to decline, which is the saying goes, "not durable."
But this piece of aluminum looks alright - the graphene battery excels at this point: If a charge-discharge cycle, this battery has undergone 25 million cycles, the specific capacitance is still as high as 91% Almost no loss.
If you use this smart phone battery, even if charging 10 times a day, can be used for nearly 70 years.
'This aluminum-graphene' super 'battery has much higher rate performance and longer cycle life than other batteries, offering higher energy density, comparable rate performance and cycle life than supercapacitors. "
Aluminum battery system took a big step forward
Aluminum is the most abundant metal in the earth's crust and is inexpensive and safe, making it an ideal anode material for battery production, but over the years the overall performance of aluminum cells has not been as good as lithium-ion batteries and supercapacitors. The key issue is Designing a cathode material that works well with aluminum and works efficiently can really deliver excellent electrochemical performance.
In 2015, Dai Hongjie at Stanford University published a paper entitled "High Temperature Pyrolysis Graphite Foam for Positive Electrodes," which was published in Nature magazine for the first time to achieve a specific capacity and long cycle of aluminum ion batteries. Olefin film to produce aluminum battery electrode.
After a year and a half exploration and accumulation, the superb team put forward the design principle of "three, three and three continuous" graphene cathode material.
'Three highs and three consecutive' design principles
'The performance of a battery depends crucially on the state of electrons and ions' running' between the positive and negative electrodes. "Superb says that the electrode material should allow as much electrons and ions to run freely or quickly homing. 'Three high' refers to the high-quality, high-oriented, high-porosity of the microstructure; 'Three-continuous' refers to a macroscopic structure with a continuous conductive network and continuous ion transport channels And continuous ion channeling.
This design principle makes aluminum - graphene battery performance a big step forward before the specific capacity of aluminum batteries has been hovering around 60mAh / g, repeated charge and discharge times can be less than thousands of times.
Commercialization still challenges
'Now some smart phones also have fast charge function, it seems that the battery is full soon, the actual battery life is not long.' Super said, and this new battery now laboratory data is 1.1 seconds can be fully charged, than the capacity Slight loss
This shows that in the future, if you use a cell phone, it will be possible to charge a 5-second call for 2 hours, but you are super-challenged by the real commercialization and require more hard work and investment from more scientists.
Superb said that the current cathode than the capacity, output voltage and area load there is still much room for improvement, the energy density is not enough to rival lithium-ion batteries in the future still need to maintain high power density to further improve the energy density. In addition, the current classic ionic liquid electrolyte is more expensive, if you can find cheaper electrolytes, the business prospects of aluminum ion batteries will be more broad.
