Suppressing Jahn-Teller distortion and phase transition of K0.5MnO2 by K-site Mg substitution for potassium-ion batteries

Luo, Rui-Jie; Li, Xun‐Lu; Ding, Jieying; Bao, Jian; Ma, Cui; Du, Chong-Yu; Cai, Xin-Yin; Wu, Xiaojing; Zhou, Yong‐Ning

doi:10.1016/j.ensm.2022.02.027

Cited by 37 publications

(12 citation statements)

References 18 publications

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“…When charging to 4.2 V, the (003) and (006) diffraction peaks are still obvious, which is in sharp contrast to the disappearance in KMO. In addition, HE-KMO just undergoes the (003) and (006) peaks shift in the subsequent discharge and charge processes, and no new diffraction peak and even peak split are observed. ,, These results show that HE-KMO is not only free of lattice distortion in the original state but also free of lattice distortion and phase transition in the whole charge–discharge process, suggesting excellent structural stability and reversibility.…”

Section: Resultsmentioning

confidence: 67%

“…In addition, HE-KMO just undergoes the (003) and (006) peaks shift in the subsequent discharge and charge processes, and no new diffraction peak and even peak split are observed. 41,47,48 These results show that HE-KMO is not only free of lattice distortion in the original state but also free of lattice distortion and phase transition in the whole charge−discharge process, suggesting excellent structural stability and reversibility. The thermal stability of fully charged KMO and HE-KMO was evaluated by differential scanning calorimetry (DSC).…”

Section: Resultsmentioning

confidence: 70%

“…In fact, layered Mn-based oxides always suffer from Jahn–Teller distortion derived from the high-spin Mn 3+ electron structure (t 2g 3 e g 1 ) in both elongated and compressed MnO 6 octahedron, which leads to distorted crystal structures. − The XRD patterns and corresponding Rietveld refinement of KMO are shown in Figure f, and the corresponding refined crystal parameters are listed in Table S4. KMO shows a distorted P′3-type phase structure with a C 2/ m space group, and the lattice parameters are refined to be a = 5.21829 Å, b = 2.75908 Å, and c = 7.16494 Å .…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

High Entropy-Induced Kinetics Improvement and Phase Transition Suppression in K-Ion Battery Layered Cathodes

Chu,

Shao,

Tian

et al. 2023

ACS Nano

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promising cathode candidate materials for K-ion batteries (KIBs) in terms of their rich raw materials and low price, while their further applications are restricted by sluggish kinetics and poor structural stability. Here, the high-entropy design concept is introduced into layered KIB cathodes to address the above issues, and an example of high-entropy layered K 0.45 Mn 0.60 Ni 0.075 Fe 0.075 Co 0.075 Ti 0.10 Cu 0.05 Mg 0.025 O 2 (HE-KMO) is successfully prepared. Benefiting from the highentropy oxide with multielement doping, the developed HE-KMO exhibits half-metallic oxide features with a narrow bandgap of 0.19 eV. Increased entropy can also reduce the surface energy of the {010} active facets, resulting in about 2.6 times more exposure of the {010} active facets of HE-KMO than the low-entropy K 0.45 MnO 2 (KMO). Both can effectively improve the kinetics in terms of electron conduction and K + diffusion. Furthermore, high entropy can inhibit space charge ordering during K + (de)insertion, and the transition metal−oxygen covalent interaction of HE-KMO is also enhanced, leading to suppressed phase transition of HE-KMO in 1.5−4.2 V and better electrochemical stability of HE-KMO (average capacity drop of 0.20%, 200 cycles) than the low-entropy KMO (average capacity drop of 0.41%, 200 cycles) in the wide voltage window.

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Section: Resultsmentioning

confidence: 67%

Section: Resultsmentioning

confidence: 70%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

High Entropy-Induced Kinetics Improvement and Phase Transition Suppression in K-Ion Battery Layered Cathodes

Chu,

Shao,

Tian

et al. 2023

ACS Nano

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“…Another notable phenomenon is the discrepancy in average discharge voltage (ADV), as shown in Figure c and d. The ADV of K 0.8 Mn 0.8 Ti 1.2 O 4 reaches 3.0 V, which is higher than that of K 0.4 MnO 2 (2.5 V) and most of the Mn/Fe/Co/Cr-based layered oxides in PIBs (Table S4). ,,,− Intriguingly, the ADV of Ni-based K 0.8 Ni 0.4 Ti 1.6 O 4 is as high as 3.6 V at cutoff voltages of 1.5–4.5 V. The increase of operating voltage is highly correlated with the corrugated layered structure because it efficiently screens the K + –K + electrostatic repulsion.…”

mentioning

confidence: 99%

“…(c) Comparison of the normalized discharge profiles of K 0.8 Mn 0.8 Ti 1.2 O 4 and K 0.8 Ni 0.4 Ti 1.6 O 4 with P′2-K 0.4 MO 2 . (d) Comparison of the working voltages of K 0.8 Mn 0.8 Ti 1.2 O 4 and K 0.8 Ni 0.4 Ti 1.6 O 4 with other reported layered oxides for PIBs, including K 2 Ni 2 TeO 6 , K 0.7 Mn 0.7 Ni 0.3 O 2 , K 0.6 CoO 2 , K 1.39 Mn 3 O 6 , K 0.5 MnO 2 , K 0.69 CrO 2 , K 0.5 Mn 0.8 Mg 0.2 O 2 , and K 0.65 Fe 0.5 Mn 0.5 O 2 . (e) Rate capability of K 0.8 Mn 0.8 Ti 1.2 O 4 and P′2-K 0.4 MO 2 .…”

mentioning

confidence: 99%

Corrugated Layered Titanates as High-Voltage Cathode Materials for Potassium-Ion Batteries

Liao

Sheng

et al. 2022

ACS Materials Lett.

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Layered transition metal oxides with two-dimensional diffusion pathway and high theoretical energy density are promising cathode candidates for potassium-ion batteries (PIBs). Nevertheless, the large size of K+ increases the K+–K+ electrostatic repulsion in the layered structure, resulting in the low operating voltage in PIBs, which remains a great challenge to be solved. Herein, we develop a series of corrugated layered titanates that extend the K+–K+ distance to ∼3.9 Å, exceeding the K+–K+ distance of all reported layered oxides. By shielding the K+–K+ electrostatic repulsion, K0.8Mn0.8Ti1.2O4 and K0.8Ni0.4Ti1.6O4 as corrugated layered titanate representatives furnish high working voltages of 3.0 and 3.6 V, respectively. In addition, K0.8Mn0.8Ti1.2O4 also achieves a large reversible capacity of 77.8 mAh g–1 and a long lifetime over 300 cycles. In situ X-ray diffraction measurements indicate that K0.8Mn0.8Ti1.2O4 exhibits reversible structural evolution during de/potassiation with a lattice volume change as low as 1.4%. These findings provide new insights for the further development high-voltage layered cathodes for PIBs.

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In Situ Structure Modulation of Cathode‐Electrolyte Interphase for High‐Performance Potassium‐Ion Battery

Li,

Gu,

Cui

et al. 2024

Adv Funct Materials

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Manganese‐based layered oxide cathodes, particularly KxMnO2 (KMO), have shown great potential in potassium‐ion batteries (PIBs) due to their low cost, high theoretical capacities, and excellent thermal stability. However, Jahn‐Teller distortion, manganese dissolution, and interface instability of electrode/electrolyte lead to structural instability and performance decay. Here, lithium difluoro(oxalate) borate (LiDFOB) is introduced as an electrolyte additive to improve the electrochemical performance of P3‐type KMO. LiDFOB creates a uniform, thin, and robust cathode‐electrolyte interphase layer on the cathode surface, enhancing reaction kinetics, preventing manganese dissolution, and stabilizing the structure. The P3‐KMO cathode with LiDFOB in the basic electrolyte exhibits significantly improved electrochemical performance, such as a remarkable Coulombic efficiency of ≈99.5% and high capacity retention of 78.6% after 300 cycles at 100 mA g−1. Moreover, the full cell of P3‐KMO||soft carbon demonstrates satisfactory specific capacity and energy density. This study emphasizes the importance of interface chemistry for PIBs.

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Suppressing Jahn-Teller distortion and phase transition of K0.5MnO2 by K-site Mg substitution for potassium-ion batteries

Cited by 37 publications

References 18 publications

High Entropy-Induced Kinetics Improvement and Phase Transition Suppression in K-Ion Battery Layered Cathodes

High Entropy-Induced Kinetics Improvement and Phase Transition Suppression in K-Ion Battery Layered Cathodes

Corrugated Layered Titanates as High-Voltage Cathode Materials for Potassium-Ion Batteries

In Situ Structure Modulation of Cathode‐Electrolyte Interphase for High‐Performance Potassium‐Ion Battery

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