Effect of Calcination Temperature on a P-type Na_0.6Mn_0.65Ni_0.25Co_0.10O₂Cathode Material for Sodium-Ion Batteries

Abstract

Unstable and deficient supplies of lithium resources have led to the development of alternative battery systems such as sodium-ion batteries. Herein, P-type Na0.6Mn0.65Ni0.25Co0.10O2 cathode materials were synthesized by a co-precipitation and solid-state reaction method. When the calcination temperature was changed from 700 to 1000°C, Na0.6Mn0.65Ni0.25Co0.10O2 had a different morphology and crystalline structure; however, a P3-type structure was formed only at 700°C, and P2-type structured cathodes could be obtained at 800, 900, and 1000°C. Their electrochemical performances were evaluated with 2032 coin-type half cells. Among them, the P2-type cathode calcinated at 900°C, exhibited a high specific discharge capacity of 148 mAh g−1, and a stable cycling performance at a 0.2 C rate for 150 cycles.

Enhancing the Cycling Stability of Sodium Metal Electrodes by Building an Inorganic–Organic Composite Protective Layer

“…Therefore, a combination of an FCPL and a new stable electrolyte , could be a future direction to further improve the reversibility of an Na metal electrode for room temperature Na full cell with Na intercalation-based cathode, Na–O 2 , and Na–S batteries. To confirm the protective effect of FCPL on Na metal, we fabricated full cells with a Na 0.6 Mn 0.65 Ni 0.25 Co 0.10 O 2 cathode and observed the differences of cycling stability between bare Na and FCPL-300P–Na electrodes . As shown in Figure S10, the cell with FCPL-300P–Na delivered much higher capacity retention (91.6% at the 60th cycle) compared to the cell with bare Na anode (76.7% at the 60th cycle), which confirms the efficacy of FCPL in stabilizing Na electrode, even in a full cell.…”

Inhibition of the P3–O3 phase transition via local symmetry tuning in P3-type layered cathodes for ultra-stable sodium storage

“…The low temperature favours the formation of the P3 structure and conversely the P2 phase, suggesting a lower synthetic energy consumption for P3 oxide formation. [14][15][16] Moreover, as a special crystallographic structure related to both P2 and O3 structures, P3-type layered oxide shows better structural stability and rate performance than the O3 phase, and higher discharge capacity than the P2 phase. 17,18 However, the P3 cathode, taking P3-Na 2/3 Ni 1/3 Mn 2/3 O 2 (P3-NaNM) for example, usually suffers from the P3-O ′ 3 irreversible phase transition at a high voltage of 4.25 V, leading to the fast capacity decay during the desodiation/sodiation process.…”

Heterotrimetallic Precursor with 2:2:1 Metal Ratio Requiring at Least a Pentanuclear Molecular Assembly

“…However, it was found to suffer from numerous irreversible phase transitions during cycling, initiating the call for structural and compositional modifications. Partial substitution of Fe with other transition metals led to the discovery of P2-type Na 2/3 M 2/3 M′ 1/3 O 2 cathode materials that were found to prevent structural degradation while delivering a higher capacity. ,, Among this family of newly emerging Na-ion cathode materials, Na 2/3 Mn 2/3 Fe 1/3 O 2 (or Na 2 Mn 2 FeO 6 ) appears to be the most promising as it demonstrates the highest discharge capacity along with a durable cycle life. , …”

“…Partial substitution of Fe with other transition metals led to the discovery of P2-type Na 2/3 M 2/3 M′ 1/3 O 2 cathode materials that were found to prevent structural degradation while delivering a higher capacity. 12,14,24 Among this family of newly emerging Na-ion cathode materials, Na 2/3 Mn 2/ 3 Fe 1/ 3 O 2 (or Na 2 Mn 2 FeO 6 ) appears to be the most promising as it demonstrates the highest discharge capacity along with a durable cycle life. 25,26 Nevertheless, there are still a number of challenges for the efficient synthesis of quaternary oxides that contain two different 3d transition metals.…”