Green synthesis of CoZn(VO<sub>4</sub>)<sub>2</sub> nanosheet for high-performance Li and Na-Ion batteries
Poster-In-person · Withdrawn
Abstract
The remarkable rise in the demand for rechargeable batteries has resulted in a notable exploration of novel electrode materials that show improved coulombic efficiency, energy density, and stability [1]. Transition-metal vanadate oxides with a variety of cations and multiple valence states have recently exhibited exceptional electrochemical performance. This can be attributed to the complexity of their chemical composition, the complementary behaviour of various types of metal, the structural flexibility, and their interfacial properties [2]. In this study, the green synthesis of cobalt zinc ortho vanadate (CoZn(VO4)2) nanosheets (CZVO) was achieved by a simple coprecipitation method followed by annealing at 300 °C.
In a synthesis, Co(CH₃CO2)₂.4H2O, Zn(NO₃)₂·6H₂O, and NH₄VO₃ were reacted at 120 °C in aqueous solution with vigorous stirring for 24h, maintaining a pH of approximately 7. The obtained yellowish powder was washed with ethanol and deionised water, followed by annealing at 300 °C. Further material characterisation confirms the structure and elements of CZVO. The electrochemical evaluation is performed on the fabricated CR2016-type half and full coin. Li-ion half-cells were constructed using Li foil as the counter electrode, while full cells were assembled with LiFePO₄ (LFP) cathodes. Na-ion half-cells were created employing Na foil as the counter electrode.
Electrochemical tests conducted in lithium half-cells (0.01–3.0 V) demonstrated that CZVO delivered a discharge capacity of 579.37, 297.59, 176.4584, 116.2976, and 34.2891 mAh g⁻¹, tested at 1 C, 2.5 C, 5 C, 10 C, and 20 C rates, respectively. CZVO||LFP full-cell (1.0 V–3.62 V) exhibited a discharge capacity of 263.4299 mAh g⁻¹ at 2.5 C rate, equating to an energy density of ~608 Wh Kg⁻¹ of cathode active material (7.03 mg cm⁻2). Comparative Na-ion half-cell tests of the CZVO operated at a 2.5 C rate demonstrated a discharge capacity of 184.43 mAh g⁻¹ compared to 297.59 mAh g⁻¹ in Li-ion cells with equivalent current and mass of active material, emphasizing the improved lithium storage capacity of this system. Ex-situ analyses, such as time-of-flight secondary ion mass spectrometry (ToF-SIMS), are being conducted to investigate lithium distribution and the formation of the solid electrolyte interphase (SEI).
In a synthesis, Co(CH₃CO2)₂.4H2O, Zn(NO₃)₂·6H₂O, and NH₄VO₃ were reacted at 120 °C in aqueous solution with vigorous stirring for 24h, maintaining a pH of approximately 7. The obtained yellowish powder was washed with ethanol and deionised water, followed by annealing at 300 °C. Further material characterisation confirms the structure and elements of CZVO. The electrochemical evaluation is performed on the fabricated CR2016-type half and full coin. Li-ion half-cells were constructed using Li foil as the counter electrode, while full cells were assembled with LiFePO₄ (LFP) cathodes. Na-ion half-cells were created employing Na foil as the counter electrode.
Electrochemical tests conducted in lithium half-cells (0.01–3.0 V) demonstrated that CZVO delivered a discharge capacity of 579.37, 297.59, 176.4584, 116.2976, and 34.2891 mAh g⁻¹, tested at 1 C, 2.5 C, 5 C, 10 C, and 20 C rates, respectively. CZVO||LFP full-cell (1.0 V–3.62 V) exhibited a discharge capacity of 263.4299 mAh g⁻¹ at 2.5 C rate, equating to an energy density of ~608 Wh Kg⁻¹ of cathode active material (7.03 mg cm⁻2). Comparative Na-ion half-cell tests of the CZVO operated at a 2.5 C rate demonstrated a discharge capacity of 184.43 mAh g⁻¹ compared to 297.59 mAh g⁻¹ in Li-ion cells with equivalent current and mass of active material, emphasizing the improved lithium storage capacity of this system. Ex-situ analyses, such as time-of-flight secondary ion mass spectrometry (ToF-SIMS), are being conducted to investigate lithium distribution and the formation of the solid electrolyte interphase (SEI).
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· 473Presenters
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Mohd Saqib
- INDIAN INSTITUTE OF TECHNOLOGY DELHI