Status : Verified
| Personal Name | Garcia, Jayson S. |
|---|---|
| Resource Title | Performance evaluation of O3-type layered transition-metal oxides [Na(NixFe(1–x)/2Mn(1–x)/2)1–yCuyO2] as cathode active materials for sodium-ion batteries |
| Date Issued | 1 June 2025 |
| Abstract | As the immediacy of the climate crisis becomes ever more apparent, battery energy storage systems can hold the key to transitioning to a renewable-fueled world. Sodium-ion batteries (SIBs) are next-generation batteries that can supplement lithium-ion batteries and are a sustainable technology that relies on earth-abundant resources such as sodium. One promising class of SIBs’ cathode active materials (CAMs) is layered transition-metal oxides (LTMOs) with chemical formula NaxMO2 (x ≤ 1 and M = transition metal/s). Although LTMOs have excellent specific capacities due to their light elemental composition and high packing densities, these materials suffer from chemical instabilities due to air exposure and from capacity degradation during cycling operation. Thus, this work evaluated LTMOs [Na(NixFe(1–x)/2Mn(1–x)/2)1–yCuyO2] by investigating the effects of (1) post-synthesis treatment, (2) nickel concentration, and (3) copper concentration on the electrochemical performance of LTMOs as CAMs for SIBs. First, NaNi0.30Fe0.35Mn0.35O2 was synthesized through the scalable method of hydroxide coprecipitation followed by calcination and was subjected to different post-synthesis treatments (i.e., recalcination, water washing, ethanol washing, and ethylene glycol washing) to reduce residual Na species introduced during synthesis. Among the materials, the ethylene glycol-washed NaNi0.30Fe0.35Mn0.35O2 had the highest initial discharge capacity of 123.9 mAh g–1 (vs. 103.5 mAh g–1 of the as-synthesized material), due to the removal of most residual alkali with minimal extraction of active Na+ from the LTMO structure. Second, NaNixFe(1–x)/2Mn(1–x)/2O2 was synthesized with varying Ni amount (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6) to study the electrochemical contribution of Ni in the Ni-Fe-Mn system. Among the materials, the NaNi0.20Fe0.40Mn0.40O2 delivered an initial discharge capacity of 120 mAh g–1 and the highest capacity retention of 73% after 100 cycles. The |
| Degree Course | Master of Science in Energy Engineering |
| Language | English |
| Keyword | energy storage; battery; sodium ion; electrochemistry |
| Material Type | Thesis/Dissertation |
Preliminary Pages
889.55 Kb
Category : F - Regular work, i.e., it has no patentable invention or creation, the author does not wish for personal publication, there is no confidential information.
Access Permission : Open Access