2026-10-11T14:40:23Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34047246 2026-10-01T17:04:50Z category_4 category_915 category_7 category_15 category_16 category_24 category_272 category_873 category_45 category_734 portal_63 item_type_6 month_year_10_2026

Tuning High-Voltage Cu–Fe Redox in P2-Type Layered Metal Oxide Cathodes for Sodium-Ion Batteries Hina Parappan (25157532) Greeshma Caroline (25157535) Shantikumar V. Nair (1665844) Senthilkumar Baskar (14864412) Biochemistry Physical Sciences not elsewhere classified Medicine Neuroscience Physiology Evolutionary Biology Environmental Sciences not elsewhere classified Chemical Sciences not elsewhere classified Sociology Biological Sciences not elsewhere classified type layered oxides superior rate capability irreversible phase transitions ion battery systems improving electrochemical reversibility gained significant attention compositional engineering strategy based systems offer limiting reversible capacity redox couples maintains low sodium content high operating voltage 7 </ sub 6 </ sub 3 </ sub 2 </ sub 1 </ sub ion batteries p2 4 +</ sup 3 +</ sup excellent cycling stability structural stability restricted capacity redox couple redox activity tuning high term durability synergistic involvement study highlights promising pathway high voltages durable sodium cycling performance cathode demonstrates 54 v P2-type layered oxides have gained significant attention in energy storage applications due to their superior rate capability and cycling performance. However, P2-type layered oxides suffer from low sodium content and irreversible phase transitions at high voltages, limiting reversible capacity and long-term durability. Although Cu–Mn-based systems offer a high operating voltage through the Cu²⁺/Cu³⁺ redox couple, the accessible voltage window remains narrow, resulting in restricted capacity. In this work, we employ a compositional engineering strategy by introducing Fe into the Cu–Mn framework to enhance both structural stability and redox activity. Fe incorporation enhances structural stability and redox activity by introducing additional cationic redox centers. The synergistic involvement of the Cu²⁺/Cu³⁺ and Fe³⁺/Fe⁴⁺ redox couples maintains a high average voltage (∼3.54 V) while improving electrochemical reversibility. The resulting P2–Na_0.7Cu_0.3Mn_0.6Fe_0.1O₂ cathode demonstrates a reversible capacity exceeding ∼90 mAh g^–1 when combined with CNTs, along with excellent cycling stability. Ex situ XRD analysis reveals reversible phase evolution, confirming enhanced structural robustness during cycling. This study highlights the effectiveness of Fe substitution in optimizing Cu–Mn cathode chemistry, offering a promising pathway for high-energy and durable sodium-ion battery systems. 2026-10-01T00:00:00Z Text Journal contribution 10.1021/acsomega.6c08581.s001 https://figshare.com/articles/journal_contribution/Tuning_High-Voltage_Cu_Fe_Redox_in_P2-Type_Layered_Metal_Oxide_Cathodes_for_Sodium-Ion_Batteries/34047246 CC BY-NC 4.0