Rational Design of a P2-Type Spherical Layered Oxide Cathode for High-Performance Sodium-Ion Batteries

Abstract

Sodium-ion batteries (SIBs) have been regarded as the most promising candidates for the next-generation energy storage devices owing to their low price and high abundance. However, the development of SIBs is mainly hindered by the instability of cathode materials. Here, we report a new P2-type manganese-rich cathode material, Na0.66Li0.18Mn0.71Mg0.21Co0.08O2 (P2-NaLiMMCO) with uniform spherical structure prepared via a simple solvothermal method and subsequent solid-state reaction. This P2-NaLiMMCO cathode material with uniform microsize secondary spheres and nanosize primary crystalline particles delivers a high initial discharge capacity of 166 mA h g–1 and superior capacity retention, which are superior to most previously reported results. The improved stability of the cathode material was further investigated by the in situ X-ray diffraction technique, which suggests an enhanced reversibility of the cathode material during the desodiation/sodiation process. With the superior electrochemical performance and stable structures, this new P2-NaLiMMCO can serve as a practical cathode material for SIBs.

Modifying redox properties and local bonding of Co3O4 by CeO2 enhances oxygen evolution catalysis in acid

“…16 ) reveal the first-order power law relationship between the three cathodic peak current densities and the scan rate (Fig. 3b inset), suggesting that the C3 peak is associated with a surface capacitive process 49 , 50 . Thus, this crucial third redox feature of Co 3 O 4 corresponds to a 2 e – /3 H + surface capacitive process of Co IV Co III ↔ IV Co IV , consistent with the proposed structural motifs in Supplementary Fig.…”

Oxide cathodes for sodium‐ion batteries: Designs, challenges, and perspectives

“…Wang and coworkers synthesized a new P2-type Na 0.66 Li 0.18 Mn 0.71 Mg 0.21 Co 0.08 O 2 cathode with nanosize primary crystalline particles and secondary spheres with uniform microsize via the solvothermal method and a solid-state reaction. 170 It delivers high initial discharge capacity (166 mAh g −1 ) and superior retention (82% after 100 cycles at 20 mA g −1 ). The in situ XRD patterns suggest that a stable and highly reversible P2-type structure is maintained during the desodiation/sodiation process (Figure 13A).…”

“…In the meantime, it also presents a large discharge capacity of 134 mAh g −1 at 1 C and 75% retention after 150 cycles at 0.5 C. The energy density of this cathode is up to 640 mAh g −1 , which is comparable to that of LIBs. Wang and coworkers synthesized a new P2‐type Na 0.66 Li 0.18 Mn 0.71 Mg 0.21 Co 0.08 O 2 cathode with nanosize primary crystalline particles and secondary spheres with uniform microsize via the solvothermal method and a solid‐state reaction 170 . It delivers high initial discharge capacity (166 mAh g −1 ) and superior retention (82% after 100 cycles at 20 mA g −1 ).…”

Progress of the Elements Doped NaFeO2Cathode Materials for High Performance Sodium‐ion Batteries

“…[20,23] The vacancies in the Na layer are generated due to extraction of sodium ions; the transition metal (TM) ions are prone to migration [24] and can easily result in an irreversible structure and poor electrochemical properties. [25][26][27] However, the stability and excellent performance of cathode materials in SIBs are limited.…”