Agar + sponge, help methanol fuel cells say goodbye to "explosive" temper
Scientists synthesized and applied a new type of composite material to develop a self-breathing direct methanol fuel cell that is safe, durable, adaptable and has excellent flexibility, avoiding safety problems such as battery explosion and fire.
In recent years, with the rapid development of portable wearable electronic devices, safe and flexible batteries have become the focus of scientists' research.
But whether it is a lithium-ion battery or a methanol fuel cell, like gasoline and gunpowder, if it is not "tamed", there will be potential safety hazards.
So how to tame this fierce horse?
A reporter from Science and Technology Daily learned from the Suzhou Institute of Nanotechnology and Nano-Bionics, Chinese Academy of Sciences on March 28 that the team of researcher Zhou Xiaochun synthesized and applied a new type of composite material to develop a safe, durable, adaptable and flexible self- The breathing direct methanol fuel cell avoids safety problems such as explosion and fire.
The results were recently published in the international authoritative journal Advanced Energy Materials.
Traditional materials cannot solve the problem of methanol leakage in batteries
Fuel cells have high energy conversion efficiency, low pollution, high power, quiet and reliable, and have a wide range of application prospects, such as electric vehicles, computers, household appliances, etc. Even in the 1960s, they have been successfully used in Apolloden Moon spacecraft, emerging in the aerospace field.
Recently, fuel cells have caught the express train of new energy, and the exposure is getting higher and higher.
Methanol fuel cell is a type of fuel cell.
Methanol fuel cells can be divided into two types: passive and active. Active methanol fuel cells rely on a pump to transport liquid methanol to the anode, while passive methanol fuel cells abandon this bulky "oil bottle", relying on capillary action, liquid methanol The anode is supplied by methods such as methanol evaporation and the gravity of the fuel itself.
However, we all know that methanol is an "explosive" temper. If used improperly, methanol leakage may lead to fire or even explosion.
After extensive exploration, scientists have found many ways to solidify liquid methanol and prevent it from leaking, such as using sponges or gels to absorb methanol.
However, ordinary gels will shrink greatly in volume after releasing methanol, and their stress is too low to maintain the original shape; while sponges have strong liquid absorption capacity and strong shape retention capacity, they retain liquid. The ability is weak, and under a certain pressure, methanol is easily squeezed out of the sponge.
Therefore, there is a need for a new type of material that can quickly absorb and solidify a large amount of liquid methanol, and is not easy to leak methanol when the battery system is compressed, needled, and cut.
New material makes fuel cells both safe and flexible
Zou Siyi, a graduate student in Zhou Xiaochun's team, synthesized a new type of composite material of agar gel and wood sponge, that is, a gel/sponge composite material, which is expected to overcome the "explosive" temper of methanol.
The preparation process of the composite material is simple.
First, dissolve the agar powder in high-purity water to obtain the agar gel solution, then pour the agar gel solution into the wooden sponge, let it stand for a period of time under vacuum conditions, so that the gel can fully enter the sponge holes, and finally obtain the gel /sponge composite.
Due to the unique composition and structure, the new composite material has the advantages of high methanol absorption rate, fast absorption speed, good cycle performance, high energy content, and also has a strong retention capacity for methanol solution.
Using the excellent water-locking ability of the gel and the strong water absorption of the sponge, Zhou Xiaochun's team successfully developed a self-breathing direct methanol fuel cell that is safe, durable, adaptable and has excellent flexibility.
In a series of destructive tests, the methanol fuel cell withstood tests including long needle piercing, cutting, bending and compression.
The new composite material can absorb and retain methanol solution, so there is no fuel leakage during destructive testing, avoiding safety problems such as explosion and fire.
Zhou Xiaochun told reporters that this concept of using absorbing materials to solidify gaseous or liquid fuels can be generally applied to improve the safety, adaptability and flexibility of other fuel cells.