Rechargeable aluminum ion batteries in the next generation of energy systems because of the advantages of low cost, high safety, high capacity of aluminum metal anode, etc. Charging 5 minutes, call 2 hours of advertising, aluminum ion batteries, but is Piece of cake.
Figure 1. Ultra-fast charging aluminum ion battery
The problem is: aluminum ion battery cathode material with lower capacity, and short service life, the ratio of discharge capacity is not strong, is an important impediment to the commercialization of aluminum ion batteries.
In view of this, the Zhejiang University superb research group developed a high-quality special structure graphene cathode material, build ultra-high performance aluminum ion battery.
Figure 2. Graphene cathode material design
The researchers first prepared by gravimetric coating or wet-spinning graphene oxide liquid crystal solution of graphene oxide film, and then through chemical reduction and high temperature annealing, prepared reduced graphene oxide film.
The high degree of assembly of the reduced graphite oxide film, which gives it a highly oriented structure, guarantees high mechanical strength and Young's modulus.High-temperature annealing and accompanying gas pressure ensure flawless high-quality and high-channel construction for higher Capacity, continuous electron transfer, continuous ion diffusion, and continuous electrolyte permeability, as well as a faster redox reaction between the reaction liquid and the electrolyte.
Fig.3 Structural characterization of graphene cathode material
The positive electrode was cycled 250,000 cycles at an ultra-high current density of 400 A g-1 (1.1 s) and achieved a specific capacity of 120 mAh g-1 with a capacity retention of 91.7%. Meanwhile, at 400 A g -1 (1.1 s) at a current density, the rate discharge capacity reached 111 mAh g-1. The recording was broken at rate discharge capability and cycle performance.
Figure 4 electrochemical properties of graphene cathode material
Figure 5. Aluminum-graphene battery performance
Al-graphene cells based on this cathode material assembly work well at all weather temperatures of -40-200 ° C and have good flexibility to accommodate up to 10,000 folds for a variety of wearable electronics.
In summary, this study points the way for super-battery research!