Li-Substituted Layered-Spinel Cathode Material for Sodium-Ion Batteries.
Additional Funding Sources
The project described was supported by Claire Xiong's Local fund at Boise State University.
Abstract
Sodium-ion batteries (SIBs) are an attractive alternative to Lithium-ion batteries (LIBs), due to the low cost, high abundance, and decreased toxicity of the materials used. However, the performance of SIBs are inferior to LIBs because the large size and high standard potential of Na ions provide lower power density and energy density. In search for a cathode material with improved electrochemical performance, previous researchers discovered that the layered cathode composed of Na(NixFeyMnz)O2 (NFM) exhibits high specific capacities, but low cycling stability and inferior rate capability at high voltages. To increase the performance of the layered cathode, lithium was substituted into the structure to create a layered-tunneled intergrown cathode (LS-NFM) consisting of both layered and spinel phases. The electrochemical performance of LS-NFM displayed increased capacities and enhanced rate capability when compared to an undoped NFM control electrode. This increased performance was due to the connectivity of the two structures that improved the charge transport kinetics by creating a shorter diffusion path for Na ions. In addition to transition metal substitution and modification of stoichiometry within the single layered structure, this study provides a unique approach to cathode structure design that can significantly increase the electrochemical performance of cathode materials in SIBs.
Li-Substituted Layered-Spinel Cathode Material for Sodium-Ion Batteries.
Sodium-ion batteries (SIBs) are an attractive alternative to Lithium-ion batteries (LIBs), due to the low cost, high abundance, and decreased toxicity of the materials used. However, the performance of SIBs are inferior to LIBs because the large size and high standard potential of Na ions provide lower power density and energy density. In search for a cathode material with improved electrochemical performance, previous researchers discovered that the layered cathode composed of Na(NixFeyMnz)O2 (NFM) exhibits high specific capacities, but low cycling stability and inferior rate capability at high voltages. To increase the performance of the layered cathode, lithium was substituted into the structure to create a layered-tunneled intergrown cathode (LS-NFM) consisting of both layered and spinel phases. The electrochemical performance of LS-NFM displayed increased capacities and enhanced rate capability when compared to an undoped NFM control electrode. This increased performance was due to the connectivity of the two structures that improved the charge transport kinetics by creating a shorter diffusion path for Na ions. In addition to transition metal substitution and modification of stoichiometry within the single layered structure, this study provides a unique approach to cathode structure design that can significantly increase the electrochemical performance of cathode materials in SIBs.
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