Abstract
Using inorganic fibrous membranes as protective layers has yielded success in suppressing dendrite growth. However, conventional fibrous membranes usually have large voids and low affinity for Li, promoting inhomogeneous charge distribution and allowing some dendrites to grow. Herein, we introduce a highly aligned TiO2/SiO2 (A-TS) electrospun nanofiber membrane as a protective layer for the Li metal anode. The A-TS membrane is fabricated by a custom-made electrospinning system with an automatic fiber alignment collector that allows control of the fibers’ orientation. At the scale of the individual fibers, their high binding energies with Li can attract more “dead” Li by reacting with the SiO2 component of the composite, avoiding uncontrollable deposition on the metal anode. At the membrane scale, these highly ordered structures achieve homogeneous contact and charge distribution on the Li metal surface, leaving no vulnerable areas to nucleate dendrite formation. Additionally, the excellent mechanical and thermal stability properties of the A-TS membrane prevent any potential puncturing by dendrites or thermal runaway in a battery. Hence, an A-TS@Li anode exhibits stable cycling performance when used in both Li–S and Li–NCM811 batteries, highlighting significant reference values for the future design and development of high-energy-density metal-based battery systems.
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•A highly aligned lithiophilic TiO2/SiO2 (A-TS) electrospun nanofiber membrane is developed.•A custom-made electrospinning system is introduced to control the orientation of the fibers in the membrane.•Suppressing dendrite growth at both membrane and fiber scales to achieve excellent cycling performance in various batteries.