High Performance Hollow Interface Microstructure New Anode Material for Aluminum

Recently, Tang Yongbing, a researcher at the Functional Film Materials Research Center of the Institute of Advanced Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, and his research team have successfully developed a metal aluminum foil negative electrode material with a hollow interface structure, which has been applied to high-efficiency, low-cost dual-ion batteries.

Tang Yongbing introduced that this new type of structure effectively solves the problem of the volume expansion and poor cycling performance of low-cost metal anode materials during charge and discharge. Related Research Results The ultra-stable solid electrolyte layer formed by the foamed paper-like interface design and its application in high-efficiency dual-ion batteries have been published online in Advanced Materials, a top journal of materials science.

With the rapid development of the market size of portable electronic devices and electric vehicles, the demand for high-energy density, low-cost secondary batteries has become increasingly urgent. At present, commercial lithium ion batteries are mostly made of graphite anode materials, the theoretical specific capacity is only 372 mAh g-1, and the compact density is low, which limits the further increase of energy density of lithium ion batteries.

It is reported that through the alloying/dealloying reaction with lithium ions, the inexpensive metal anode generally has a larger specific capacity and is expected to obtain a higher energy density. "The theoretical specific capacity of aluminum is as high as 2234 mAh g-1 (Li9Al4), and it is rich in reserves and low in price." Tang Yongbing said, "However, aluminum anodes will have a certain volume expansion during battery reaction, which will affect the cycling of batteries. stability."

Based on the above considerations, Tang Yongbing and his team members Qin Panpan, Wang Meng, Li Na, and others successfully developed a metal aluminum foil material with a hollow interface microstructure, and at the same time, it integrated the active material and current collector and designed it. Successfully applied to new high-efficiency, low-cost dual-ion secondary batteries.

Tang Yongbing said: “We use structural design, modified aluminum foil as negative electrode active material and current collector, expanded graphite as positive electrode, and using conventional electrolyte. Compared to traditional lithium-ion batteries, this new secondary energy storage battery has higher The operating voltage (average discharge voltage is ~4.2 V), while significantly increasing the proportion of active material and energy density, and significantly reducing the manufacturing costs, and environmentally friendly."

In addition, the interface design of the hollow microstructures makes the lithium-aluminum alloy generation region successfully confined to the hollow interface, thereby effectively alleviating the volume expansion of the aluminum negative electrode during the alloying process, and obtaining a highly stable SEI film.

The results show that the new battery circulates at 1500 cycles at 2h with a half-hour charge and discharge rate, and the capacity retention rate is as high as 99%. In addition, even at a power density as high as 2113 Wkg-1, the battery has an energy density of 169 Wh. Kg-1 (10C, charge and discharge time is 6 minutes), much higher than most commercial lithium-ion batteries.

Tang Yongbing pointed out: "Our research results have guiding significance for the development of cheap metal anode materials and are expected to promote the development of high-energy, low-cost secondary batteries based on inexpensive metal anodes."