Lithium-ion Battery

Overview

With the rapid development of portable electronic devices and electric vehicles, the requirement of high energy density and small volume energy-storage devices has drawn lots of concern. Lithium-ion battery, which is the major energy-storage device nowadays, possesses the merits of high energy density, low memory effect, lightweight, and good stability. To enhance the capacity of the lithium-ion battery, scientists dedicated to the amelioration of anode materials. Techniques such as nanopowder, core-shell structure, and yolk structures have been intensively studied. Promoting battery capacity, simplifying the manufacturing process, and lowering the costs in the meantime is the ultimate goal of the invention of lithium-ion batteries.

Our strategies:
Anode Materials

Multi-walled carbon nanotube (MWCNT)-decorated WTe₂ nanostars (WTe₂@CNT nanocomposites) are first to be employed as anode candidates in the development of lithium-ion (Li-ion) batteries by our group. The exposed active interlayers of the WTe₂ nanostars are responsible for maintaining the structural integrity of the electrodes as well as buffering the large volume expansion and avoiding the agglomeration within the WTe₂ nanostars. WTe₂@CNT nanocomposites deliver a high discharge capacity of 1097, 475, 439, 408, 395, and 381 mAh g⁻¹ with an increasing current density of 100, 200, 400, 600, 800, and 1000 mA g⁻¹, respectively, which is much higher than that of WTe₂ only. Moreover, WTe₂@CNT nanocomposites exhibit a superior reversible capacity of 592 mAh g⁻¹ at 500 mA g⁻¹ with a capacity retention of 100% achieved over 500 cycles, which is superior to bare WTe₂ nanostars (~85 mAh g⁻¹ over 350 cycles).

A graphene-like structure molybdenum disulfide (S-MoS₂) was synthesized by a hydrothermal method with the decoration of zero-dimensional (0D) α-Fe₂O₃ nanoparticles. Subsequently, the three-dimensional (3D) S-MoS₂@Fe₂O₃ heterostructure exhibits the capacity of 600 mA hg⁻¹ after 70 cycles, which is higher than that of bulk MoS₂ (B-MoS₂) and sheet MoS₂ (S-MoS₂). The α-Fe₂O₃ nanoparticles, acting as a spacer, not only prevent MoS₂ sheets from the stacking but also increase accessibility for electrolyte penetration to provide more active sites and lower the diffusion energy barrier for Li⁺ ions during the charge-discharge process. These S-MoS₂@Fe₂O₃ nanoparticles possess high potential for application as anode materials in next-generation lithium-ion batteries.

Recent first/corresponding-author publications:

1. ACS Sustainable Chemistry & Engineering 7 (2019) 10363-10370

2. Materials Chemistry and Physics 219 (2018) 311–317

3. Nanotechnology 31, 3(2019)