Toward Theoretically Cycling-Stable Lithium-Sulfur Battery Using a Foldable and Compositionally Heterogeneous Cathode
Lei Zhong1, Kai Yang1, Ruiteng Guan1
1The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province/State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials Science and Engineering, Sun Yat-sen University , Guangzhou 510275, P. R. China.
ACS Applied Materials & Interfaces
|November 28, 2017
Summary
Researchers developed a novel 3D sulfur cathode for rechargeable lithium-sulfur (Li-S) batteries. This design enhances conductivity and stability, improving energy storage performance for practical applications.
Area of Science:
- Materials Science
- Electrochemistry
- Energy Storage
Background:
- Rechargeable lithium-sulfur (Li-S) batteries offer high theoretical energy density, cost-effectiveness, and eco-friendliness, making them promising for next-generation energy storage.
- Current Li-S battery technology faces challenges including low sulfur utilization and poor capacity retention, hindering practical application.
Purpose of the Study:
- To design and fabricate a novel, foldable, and compositionally heterogeneous three-dimensional sulfur cathode with an integrated sandwich structure.
- To improve the electrical conductivity and electrochemical performance of Li-S batteries.
Main Methods:
- Fabrication of a three-dimensional sulfur cathode using a combination of zero-dimensional ketjen black (KB), one-dimensional activated carbon fiber (ACF), and two-dimensional graphene (G) to create multi-dimensional conductive pathways.
- Integration of sulfur within this carbon matrix in a sandwich structure.
- Electrochemical testing of the fabricated cathode, including specific capacity, rate performance, and long-term cycling stability at various sulfur loadings.
Main Results:
- The T-AKG/KB@S cathode with an areal sulfur loading of 2 mg cm⁻² demonstrated a high initial specific capacity and superior rate performance.
- Achieved a reversible discharge capacity of 726 mAh g⁻¹ at 3.6 mA cm⁻² with an exceptionally low capacity fading rate of 0.0044% per cycle after 500 cycles.
- At a higher areal sulfur loading of 8 mg cm⁻², the cathode delivered 938 mAh g⁻¹ at 0.71 mA cm⁻² with a capacity fading rate of 0.15% per cycle and nearly 100% Coulombic efficiency over 50 cycles.
Conclusions:
- The developed three-dimensional sulfur cathode effectively enhances electrical conductivity and electrochemical stability in Li-S batteries.
- The novel cathode design addresses key limitations of Li-S batteries, showing potential for high-performance, long-lasting energy storage solutions.
- The study highlights the significance of multi-dimensional carbon architectures for advancing Li-S battery technology.
