A New P2‐Type Layered Oxide Cathode with Extremely High Energy Density for Sodium‐Ion Batteries. Issue 15 (25th February 2019)

• Record Type: Journal Article
• Authors: Hwang, Jang‐Yeon; Kim, Jongsoon; Yu, Tae‐Yeon; Sun, Yang‐Kook
• Is Part Of: Advanced energy materials. Volume 9:Issue 15(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-02-25
• Subjects: high‐capacity -- high energy density -- high‐rate -- P2‐type cathodes -- sodium‐ion batteries; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201803346
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Herein, a new P2‐type layered oxide is proposed as an outstanding intercalation cathode material for high energy density sodium‐ion batteries (SIBs). On the basis of the stoichiometry of sodium and transition metals, the P2‐type Na0.55 [Ni0.1 Fe0.1 Mn0.8 ]O2 cathode is synthesized without impurities phase by partially substituting Ni and Fe into the Mn sites. The partial substitution results in a smoothing of the electrochemical charge/discharge profiles and thus greatly improves the battery performance. The P2‐type Na0.55 [Ni0.1 Fe0.1 Mn0.8 ]O2 cathode delivers an extremely high discharge capacity of 221.5 mAh g −1 with a high average potential of ≈2.9 V (vs Na/Na + ) for SIBs. In addition, the fast Na‐ion transport in the P2‐type Na0.55 [Ni0.1 Fe0.1 Mn0.8 ]O2 cathode structure enables good power capability with an extremely high current density of 2400 mA g −1 (full charge/discharge in 12 min) and long‐term cycling stability with ≈80% capacity retention after 500 cycles at 600 mA g −1 . A combination of electrochemical profiles, in operando synchrotron X‐ray diffraction analysis, and first‐principles calculations are used to understand the overall Na storage mechanism of P2‐type Na0.55 [Ni0.1 Fe0.1 Mn0.8 ]O2 . Abstract : On the basis of the stoichiometry of sodium and transition metals, pure P2‐type Na0.55 [Ni0.1 Fe0.1 Mn0.8 ]O2 is designed and synthesized as a high‐performance cathode material for sodium‐ion batteries. With smooth electrochemistry, the P2‐Na0.55 [Ni0.1 Fe0.1 Mn0.8 ]O2 cathode delivers an extremely high discharge capacity of 221.5 mAh g −1 with a high average potential of ≈2.9 V (vs Na/Na + ), outstanding cycling stability, and excellent power capability.