INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Jingfang Zhou,Pifu Gong,Mingjun Xia,Aimin Ji,Lifang Zhang,Huiqiang Wu,Qian Wu
Replacing alkali metals (K, Na atoms) by an alkaline-earth metal (Ba atom), α-Ba3Sc2(BO3)4 (high-temperature phase) is successfully obtained by a molten salt method, taking Ba2K1.6Na0.4Sc2(BO3)4 as the parent template. Although both of them exhibit similar layered structures composed of ScO6 and BO3 units, α-Ba3Sc2(BO3)4 shows largely distorted ScO6 octahedra (Δd = 0.56) forced by the uniform tension of a larger space effect from BaO12 polyhedrons, rather than regular ScO6 octahedra like in Ba2K1.6Na0.4Sc2(BO3)4. Experimental measurements and calculated analyses elucidate that distorted ScO6 octahedra in α-Ba3Sc2(BO3)4, displaying a second-order Jahn–Teller (SOJT) effect, enlarge the experimental birefringence up to 0.14@550 nm, while Ba2K1.6Na0.4Sc2(BO3)4 with regular ScO6 octahedra only shows Δn = 0.11 under the same condition. In addition, other optical and thermal properties of the two title compounds were characterized. The experimental results indicate that Ba2K1.6Na0.4Sc2(BO3)4 and α-Ba3Sc2(BO3)4 are promising birefringent materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMPHYSCHEM
·
2022
·Vol. 23
·期 6
·e202200002
·
IF 3.52
Jingfang Zhou,Rukang Li
Graphical Ba 3 Sc 2 (BO 3 ) 4 displays a beneficial layered structure in which BO 3 units are parallelly arranged by the modulation of ScO 6 octahedra and BaO n (n=9, 12) polyhedrons. The parallel arrangement of planar BO 3 units generates a large basic birefringence of 0.096, further enhanced by distorted ScO 6 octahedra up to Δn=0.149@550 nm, which is similar to the values reported in TiO 2 , LiNbO 3 , BaTi(BO 3 ) 2 . Transition metal ions with d 0 electronic states (Ti 4+ , Zr 4+ , Nb 5+ and Ta 5+ ) are widely investigated as functional materials. This work first illustrates that Sc 3+ ion, long-time ignored, displays a second-order Jahn-Teller (SOJT) effect similar to asymmetric oxide-coordinated transition metal ions, thus providing a new ground to seek for asymmetric functional materials with enhanced performances. In Ba 3 Sc 2 (BO 3 ) 4 , BO 3 groups are parallelly arranged, satisfying the ideal arrangement to produce large birefringence. Importantly, distorted octahedral ScO 6 with Sc 3+ ion in its d 0 electronic state enlarges birefringence unexpectedly up to 0.149 @ 550 nm, which is larger than previously reported borates containing solely BO 3 , even to B 3 O 6 units. Subsequently, the SOJT influence of distorted ScO 6 octahedra on birefringence is verified by a comparison between experimental data and theoretical calculations. In addition, Ba 3 Sc 2 (BO 3 ) 4 also displays a high transmittance in the range of 230 nm–3.5 μm with a UV cut-off wavelength at 198 nm and a large laser induced damage threshold (2.7 GW/cm 2 ), comparable to α-BaB 2 O 4 . Above characteristics imply that the title compound may be a promising birefringent material.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Wenxu Wang,Yue Sun,Pengcong Wen,Yueqiang Zhou,Dongyun Zhang,Chengkang Chang
This study presents a novel modification strategy involving the replacement of Mn with Sc in the cathode of NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM). The results of this study confirmed that Sc doping introduced strong Sc–O bonds to enhance the bonding between transition metal ions and O 2− . Additionally, Sc doping reduced the proportion Mn 3+ in the material (from 50.23% to 47.46%), thereby inhibiting the material structural distortion due to the Jahn–Teller effect induced by Mn 3+ . These factors were the main contributors to the improved cycling performance of the modified material. Furthermore, the introduction of Sc decreased the band gap of the material (1.7416–1.6706 eV) and the Na + activation barrier energy (0.773–0.732 eV). These changes not noly facilitated the de-embedding of Na + in the material lattice but also significantly enhanced the material electronic conductivity, leading to an excellent rate performance of the modified material. These results indicate that the NFM-Sc0.01 sample maintained an ultra-high capacity retention of 86.45% after 200 cycles at 1 C. At 5 C, the discharge capacity of NFM-Sc0.01 significantly increased from 79.3 mAh g −1 in NFM to 93.4 mAh g −1 , demonstrating great potential for industrialized applications.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Jingyao Zeng,Jinqiang Gao,Weishun Jian,Haoji Wang,Wenyuan Li,Ningyun Hong,Baichao Zhang,Jiangnan Huang,Bai Song,Chaolun Gan,Sedat Yasar,Wentao Deng,Guoqiang Zou,Hongshuai Hou,Xiaobo Ji
Na 4 Mn 1.5 Fe 1.5 (PO 4 ) 2 P 2 O 7 (NMFPP), with its low cost and high energy density, is essential for accelerating the commercialization of sodium-ion batteries. However, its practical application is limited by serious voltage hysteresis and detrimental Jahn-Teller distortions. Herein, a high operating voltage and superior stable Nb-doped NMFPP with fewer intrinsic anti-site defects are elaborately designed by the reconstruction of the crystal lattice and electronic distribution. By introducing higher charge density Nb─O bonds, the lengths of Mn-O bonds are shortened, enhancing lattice stability. As a result, the lattice volume contracted during Na + extraction/insertion is decreased with niobium-modified Na 4 (Mn 0.5 Fe 0.5 ) 2.94 Nb 0.06 (PO 4 ) 2 P 2 O 7 , mitigating lattice distortion from the Jahn-Teller effect and increasing the capacity retention after 1000 cycles from 57.5% to 82.3%. More importantly, the delayed effect of Mn 2+ involvement in redox reactions is significantly reduced, raising the average operating voltage from 3.32 to 3.64 V and increasing the overall energy density by 13%. This study opens new avenues to develop advanced sodium-ion battery cathode materials with high energy density and long calendar life for energy storage.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Yifei Chen,Meng Li,Qin Zhu,Wei Bai,Xiaofang Liu,Mingwu Xiang,Junming Guo,Jintao Liu
The Jahn-Teller effect and Mn dissolution always restrict the practical electrochemical properties of spinel LiMn 2 O 4 cathode material. Herein, a low-temperature solid-state combustion method is employed to synthesize various truncated octahedral LiZn 0.03 Al x Mn 1.97- x O 4 ( x ≤ 0.08) with submicron structure. The Zn/Al dual-doping is conducive to forming {110} and {100} planes, and is also beneficial to the crystal development of LiMn 2 O 4 . It is found that as the amount of Al doping increases, the average particle size gradually decreases from 188 nm to 113 nm. In addition, the Zn/Al co-doping integrated with small particles can improve the high-rate performance. The optimal LiZn 0.03 Al 0.03 Mn 1.94 O 4 exhibits submicron truncated octahedral morphology, high crystallinity , and good particles dispersibility . Benefiting from these structure merits, the LiZn 0.03 Al 0.03 Mn 1.94 O 4 delivers the first discharge capacity of 113.1 mAh⋅g −1 and low capacity fade of 9.9 % after 300 cycles at 1C. It also shows the high first discharge capacity of 86.6 mAh⋅g −1 at 10C and the high capacity retention of 72.1 % after 2000 cycles. Even at ultrahigh current density of 15C and 20C, the ultralong cycling lifespans over 2000 cycles are also achieved in LiZn 0.03 Al 0.03 Mn 1.94 O 4 cathode material. The excellent electrochemical properties are ascribed to its relatively high Li + diffusion coefficient (1.60 × 10 −11 cm 2 ⋅s −1 ) and low apparent activation energy (25.45 kJ⋅mol −1 ) during the de-intercalation process. The Zn/Al dual-doping and submicron truncated octahedron designs of the LiMn 2 O 4 provide a scientific reference to prepare high-performance cathode materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2021
·Vol. 15
·期 4
·3143-3149
·
IF 8.897
Huang Ruling,Xue Qing,Lin Jiao,Zhang XiXue,Zhou Jiahui,Wu Feng,Li Li,Chen Renjie
Layered Mn-based oxides are one of the promising cathode materials for potassium-ion batteries (KIBs) owing to their high theoretical capacities, abundant material supply, and simple synthesis method. However, the structural deterioration resulting from the Jahn-Teller effect of Mn ions hinders their further development in KIBs. Herein, a novel Mn-based layered oxide, K 0.54 Mn 0.78 Mg 0.22 O 2 , is successfully designed and fabricated as KIBs cathode for the first time. It delivers smooth charging/discharging curves with high specific capacity of 132.4 mA·g −1 at 20 mA·g −1 and good high-rate cycling stability with a capacity retention of 84% over 100 cycles at 200 mA·g −1 . Combining in-situ X-ray diffraction (XRD) and ex-situ X-ray photoelectron spectroscopy (XPS) analysis, the storage of K-ions by K 0.54 Mn 0.78 Mg 0.22 O 2 is revealed to be a solid-solution processes with reversible slip of the crystal lattice. The studies suggest that the rational doping of inactive Mg 2+ can effectively suppress the Jahn-Teller effect and provide outstanding structure stability. This work deepens the understanding of the structural evolution of Mn-based layered materials doped with inactive materials during de/potassiation processes.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED PHYSICS
·
2024
·Vol. 136
·期 3
·
IF 2.7
Wang L. G.,Cui H.,Zhu C. M.,Wang R.,Yu G. B.,Su X. F.,Jiang X. L.,Jiang Y.
Some spinel chromium oxides with the chemical formula ACr 2 O 4 exhibit magnetic-induced multiferroicity due to the special spiral spin order. However, because of the relatively low temperature of the ordered spiral phase, this kind of multiferroicity generally displays a limited coexistence of magnetic and ferroelectric orders in a narrow temperature range. The Jahn–Teller (JT) effect, serving as a crucial link between charge and orbit degrees of freedom, can facilitate efficient modulation of multiferroic properties. In this work, Ni 1− x Cu x Cr 2 O 4 (0 ≤ x ≤ 0.2) series are synthesized by occupying the same Wyckoff site with two kinds of JT ions. The microstructure and JT distortion can be distinctly influenced by varying the doping level of Cu 2+ ions. Particularly, Ni 0.85 Cu 0.15 Cr 2 O 4 ( x = 0.15) presents the pronounced JT distortion, accompanied by observation of dielectric anomaly at ∼78 K, resulting from spin–orbit coupling. This implies that the JT effect can significantly promote the contribution of spin–orbit coupling in magnetoelectric correlation. Moreover, the magnetodielectric effect induced by intrinsic magnetoelectric coupling is confirmed in Ni 0.85 Cu 0.15 Cr 2 O 4 over a wide temperature range of 10–200 K, which is much higher than the Néel temperature of ∼85 K. It indicates that spin–orbit coupling based on the JT effect could overcome the constraint of magnetic order to achieve effective control on electric polarization performance under an applied magnetic field, thereby showing broad application prospects.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2022
·
IF 13.599
Shu Zhang,Hongyi Chen,Jun Chen,Shouyi Yin,Yu Mei,Lianshan Ni,Andi Di,Wentao Deng,Guoqiang Zou,Hongshuai Hou,Xiaobo Ji
Spinel LiMn 2 O 4 is recognized as one of the most competitive cathode candidates for lithium-ion batteries ascribed to environmentally benign and rich sources. However, the wholesale application of LiMn 2 O 4 is predominately plagued by its severe capacity degradation, mainly associated with the innate Jahn-Teller effect. Herein, single-crystalline LiMn 2 O 4 with Eu 3+ doping is rationally designed to mitigate the detrimental Jahn-Teller distortion by tuning the chemical environment of MnO 6 octahedra and accommodating localized electron, based on the unique aspheric flexible 4 f electron orbit of rare-earth metal ions. Notably, the stretching of MnO 6 octahedron stemmed from the Jahn-Teller effect in Eu-doped LiMn 2 O 4 is effectively suppressed, confirmed by theoretical calculation. Meanwhile, the structural stability of the material has been significantly enhanced due to the robust Mn–O band coherency and weakened phase transition, proved by synchrotron radiation absorption spectrum and operando X-ray diffraction. The corresponding active cathode manifests superior long-cycle stability after 300 loops at 2C and displays only a 0.011% capacity drop per cycle even at 5C. Given this, this modification tactic sheds new light on achieving superior long-cycle performances by suppressing distortion in various cathode materials.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Lin Zhang,Chenchen Wang,Yanchen Liu,Meng Ren,Juan Du,Aibing Chen,Fujun Li
Manganese-based layered oxides are one of the most promising cathode materials for sodium-ion batteries (SIBs) due to their high specific capacity and low cost of manganese and sodium. However, they are limited by the poor cycling stability caused by irreversible phase transitions and Jahn-Teller effect of Mn 3+ . Herein, Mo-doped P2-Na 0.67 Mn 1-x Mo x O 2 suppress the irreversible phase transition of P2-OP4 resulted from gliding of MnO 2 -slabs. It reveals that no phase transition occurs under high voltage via Mo elements doping into MnO 6 -layers. P2-Na 0.67 Mn 1-x Mo x O 2 displays high cyclic stability with a high capacity retention of 86.4% after 100 cycles and improved rate performance with an average working voltage of 2.61 V. The research provides a new perspective for designing novel layered oxide cathodes design toward high-performance SIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Nano
·
2024
·
IF 15.8
Shuyu Zhou,Junhong Liao,Chenglong Yu,Pengpeng Dai,Tong Gao,Tingzheng Hou,Guozhong Cao,Shixi Zhao
The Jahn–Teller (JT) deformation triggers severe structural distortion and large capacity fading in the cathode materials of alkali-ion batteries. Although conventional doping containing over 20 dopant species has been demonstrated to suppress the JT effect, how the short-range and cooperative JT effect are regulated remains an open question. Recently, the new compositionally complex (high entropy) doping has been validated in various oxide cathodes and achieved “zero strain”, but the reported “synergistic effect” is largely factual reporting with a limited fundamental understanding of the link between multicomponents and the JT effect. By comparing a group of spinel LiMn2O4 (LMO) cathodes with tridoping sites containing one, three, or five dopants’ species, the present work shows that MnO6 octahedral distortion systematically decreases, whereas capacity retention and structure stability systematically increase as the number of dopants’ species increases. We propose the generality rules that Mn-site doping breaks the linear continuous short-range JT distortion while 16c-sites doping disturbs the dz2-orbital collinear ordering and mitigates the cooperative JT effect. Moreover, our complex doping strategy further buffers and rotates the JT strain, resulting in isotropic moderate volume distortion. Based on this synergic effect, both the short-range and cooperative JT effect are significantly suppressed in our synthesized multisites multicomponent doped LMO.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS LETTERS
·
2022
·Vol. 121
·期 20
·
IF 3.971
Guan Xiaoli,Li Hongjiang,Yu Zhiyuan,Yu Xiaohan,Jin Shuaizhao,Gu Xin,Liu Xiang
A series of La 0.7 K 0.3− x Sr x MnO 3 (0.00 ≤ x ≤ 0.3) films were fabricated on LaAlO 3 substrates using a sol-gel spin-coating technique. The relationship between electrical transport properties and a microstructure was explained via the Jahn–Teller effect, a phenomenological percolation model, and a double-exchange mechanism. The results revealed the strong impact of K and Sr co-occupying A-sites on the formation of Mn 3+ /Mn 4+ pairs, crystal structure, conductivity, surface morphology, and in-plane and out-of-plane strains. The as-fabricated La 0.7 K 0.25 Sr 0.05 MnO 3 films showed a peak temperature coefficient of resistivity of 16.63% K −1 at 298.3 K.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 17
·6827-6836
·
IF 8.067
Min Rao,Yihui Zhu,Zhiying Zhang,Tao Yang,Xiaoshi Hu,Dexuan Huo,Dexin Yang
Substitution of lead (Pb) with environmentally friendly germanium (Ge) is a very important and promising method to reduce the toxicity and improve the efficiency and stability of perovskite films for practical applications in light-emitting diodes (LEDs) and solar cells. However, a previous study shows that the efficiency of LEDs based on the germanium–lead (Ge–Pb) perovskites will decrease as the Ge content exceeds 30%, due to trap-assisted recombination. Here we demonstrate highly luminescent sky-blue Ge0.3Pb0.7-based perovskite films with photoluminescence quantum efficiencies (PLQEs) of up to 48%, showing a relative improvement of 17% over similarly prepared Ge-free, Pb-based ones. The PL stability of the Ge0.3Pb0.7-based perovskite films is also relatively improved compared to that of the Pb-based ones. The reasons of the PL efficiency and stability improvement are discussed in this study. The symmetry-adapted shear strain variations related to the suppression of the Jahn–Teller distortion after Ge substituting could play an important role in increasing the stability of the Ge-inclusion perovskites.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）