The invention pertains to O3-structured 'layered' Na-transition metal oxide (NaTMO2) cathode active material for Na-ion batteries. Specifically, it introduces a phase-pure O3-structured NaTMO2 with outstanding rate-capability and long-term electrochemical cycling stability, even at high current densities. Additionally, it includes a method for synthesizing the developed O3-structured 'layered' Na-transition metal oxide (NaTMO2) cathode material, which facilitates easy Na-transport within the structure (i.e., enhanced Na-diffusivity) while maintaining prolonged electrochemical cycling stability under high current densities.
Figure (1) The scanning electron micrograph (SEM) of the synthesized cathode material; (2) (a) Cycling stability, i.e., reversible Na-storage capacity vs. cycle number (including coulombic efficiency); (b) rate-capability, showing the variations in specific discharge capacities with current density (i.e., C-rates).
Layered sodium transition metal oxides (Na-TM-oxides) are being explored as high-capacity and high-energy-density cathode materials for Na-ion batteries. However, to make Na-ion batteries viable, it is crucial to improve not only the specific capacity and energy density but also the Na-ion transport kinetics to enhance the rate capability and power density of the cells. The O3-structured Na-TM-oxides, despite their higher initial sodium content, suffer from sluggish Na-ion transport compared to the P2-structured counterparts due to a more complicated ion transport pathway.
- Excellent Rate Capability: Exhibits very high-rate capability, making it suitable for fast-charging Na-ion battery applications.
- Phase-Pure Cathode Material: Synthesizes a phase-pure transition metal oxide (NaTMO2) that serves as a high rate-capable cathode material for Na-ion batteries.
- High Reversible Capacity and Stability: Demonstrates excellent reversible Na- storage capacity and cyclic stability, even under high current density galvanostatic cycling conditions.
- Optimized Cation Design Strategy: Provides a design strategy that combines transition metal (TM) and non-transition metal ions in the TM-layer to optimize the overall electronegativity of the cation combination.
- Enhanced Inter-Slab Spacing: Enhances the inter-slab spacing, i.e., the Na-layer thickness, in the layered Na-TM-oxide structure, facilitating easier Na+ ion transport.
A phase-pure O3-structured NaTMO2 with the composition Na(Li0.05Ni0.3Si0.05Ti0.45Cu0.1Mg0.05)O2 has been developed. This material demonstrates excellent reversible Na-storage capacity and cyclic stability, maintaining a specific discharge capacity of approximately 63 mAh/g and retaining 76% of its capacity(@2.5C rate) after 500 electrochemical cycles within a potential window of 2.0-4.0 V (vs. Na/Na+ ) in a Na half-cell configuration, even when subjected to galvanostatic cycling at very high current densities.
The invention is at the stage of Demonstration and/or validation in lab environment.
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The developed materials have a potential role in sodium-ion batteries (SIBs) a promising alternative to lithium-ion batteries (LIBs). Widespread use of SIBs can accelerate the decarbonization of the energy sector while promoting global equity and sustainability. (health/environment-friendly and cost-effective).
Na-ion batteries have a wide range of applications in many industries. They are used for energy storage for many energy sources. They also act as the batteries for portable electronic devices like smartphones or the electric vehicles.
Geography of IP
Type of IP
202321016587
457657