Nature Communications
·
2024
·Vol. 15
·期 1
·1-11
·
IF 14.7
Zeng Weihao,Xia Fanjie,Wang Juan,Yang Jinlong,Peng Haoyang,Shu Wei,Li Quan,Wang Hong,Wang Guan,Mu Shichun,Wu Jinsong
Fast-charging, non-aqueous lithium-based batteries are desired for practical applications. In this regard, LiMn 2 O 4 is considered an appealing positive electrode active material because of its favourable ionic diffusivity due to the presence of three-dimensional Li-ion diffusion channels. However, LiMn 2 O 4 exhibits inadequate rate capabilities and rapid structural degradation at high currents. To circumvent these issues, here we introduce quintuple low-valence cations to increase the entropy of LiMn 2 O 4 . As a result, the entropy-increased LiMn 2 O 4 -based material, i.e., LiMn 1.9 Cu 0.02 Mg 0.02 Fe 0.02 Zn 0.02 Ni 0.02 O 4 , when tested in non-aqueous lithium metal coin cell configuration, enable 1000 cell cycles at 1.48 A g −1 (corresponding to a cell charging time of 4 minutes) and 25°C with a discharge capacity retention of about 80%. We demonstrate that the increased entropy in LiMn 2 O 4 leads to an increase in the disordering of dopant cations and a contracted local structure, where the enlarged LiO 4 space and enhanced Mn-O covalency improve the Li-ion transport and stabilize the diffusion channels. We also prove that stress caused by cycling at a high cell state of charge is relieved through elastic deformation via a solid-solution transition, thus avoiding structural degradation upon prolonged cycling.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Advanced Energy Materials
·
2025
·
IF 26
Shaowu Huang,Jiazhuan Qin,Xinmin Yu,Qiao Li,Jiahui Yu,Limin Wu,Chunfu Lin,Renchao Che
Doping/substitution, which leads to an increase in configurational entropy, is a widely used approach to strengthen the electrochemical properties of energy-storage materials. Nevertheless, the key factor behind the enhanced cycling stability after the entropy increase remains elusive. Herein, via selective dopings of TiNb 2 O 7 (TNO), an entropy-increased Ti 0.95 V 0.05 Zr 0.05 Nb 1.9 Ta 0.05 O 7 (TNO-0.05) anode material is exploited, and an intrinsic link between the entropy increase and capacity-retention enhancement is revealed through a systematical study of this new material. As the dopant amount increases, the full-width at half-maximum of the X-ray diffraction (XRD) peaks of doped TNO monotonically widens, and thus the lattice distortion becomes severe. Significant lattice distortion with up to 427% larger lattice strain is introduced in TNO-0.05. Although the unit-cell-volume expansion of TNO-0.05 after lithiation is not reduced, the increased particle hardness, which originates from the increased lattice strain, effectively hinders particle breakage during repeated lithiation–delithiation. Consequently, TNO-0.05 delivers significantly improved cycling stability, showing approximately twice the capacity retention of TNO with a large active-material loading of 4.5 mg cm −2 after 500 cycles at 1250 mA g −1 . Clearly, the material hardening caused by the lattice distortion can solve the structure-degradation problem in intercalation electrodes, undoubtedly promoting the exploitation of long-life energy-storage materials.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2024
·Vol. 31
·期 10
·2263-2273
·
IF 5.6
Lu Dongfei,Xi Guoqiang,Li Hangren,Tu Jie,Liu Xiuqiao,Liu Xudong,Tian Jianjun,Zhang Linxing
BiFeO 3 (BFO) has received considerable attention as a lead-free ferroelectric film due to its large theoretical remnant polarization. However, BFO suffers from a large leakage current, resulting in poor ferroelectric properties. Herein, the sol–gel method was used to deposit a series of BFO-based thin films on fluorine-doped tin oxide substrates, and the effects of the substitution of the elements Co, Cu, Mn ( B -site) and Sm, Eu, La ( A -site) on the crystal structure, ferroelectricity, and leakage current of the BFO-based thin films were investigated. Results confirmed that lattice distortion by X-ray diffraction can be attributed to the substitution of individual elements in the BFO-based films. Sm and Eu substitutions contribute to the lattice distortion in a pseudo-cubic structure, while La is biased toward pseudo-tetragonal. Piezoelectric force microscopy confirmed that reversible switching of ferroelectric domains by nearly 180° can be realized through the prepared films. The ferroelectric hysteresis loops showed that the order for the polarization contribution is as follows: Cu > Co > Mn ( B -site), Sm > La > Eu ( A -site). The current density voltage curves indicated that the order for leakage contribution is as follows: Mn < Cu < Co ( B -site), La < Eu < Sm ( A -site). Scanning electron microscopy showed that the introduction of Cu elements facilitates the formation of dense grains, and the grain size distribution statistics proved that La element promotes the reduction of grain size, leading to the increase of grain boundaries and the reduction of leakage. Finally, a Bi 0.985 Sm 0.045 La 0.03 Fe 0.96 Co 0.02 Cu 0.02 O 3 (SmLa-CoCu) thin film with a qualitative leap in the remnant polarization from 25.5 (Bi 0.985 Sm 0.075 FeO 3 ) to 98.8 µC/cm 2 (SmLa-CoCu) was prepared through the synergistic action of Sm, La, Co, and Cu elements. The leakage current is also drastically reduced from 160 to 8.4 mA/cm 2 at a field strength of 150 kV/cm. Thus, based on the increasing entropy strategy of chemical engineering, this study focuses on enhancing ferroelectricity and decreasing leakage current, providing a promising path for the advancement of ferroelectric devices.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Wenzhao Wei,Donggang Wang,Haibin Sun,Fangyong Yu,Xue Guo,Qiangqiang Hu,Yurun Feng,Hongli He,Xin Kong
Medium-entropy BaZr 0.1 Ce 0.5 Y 0.2 Dy 0.2 O 3-δ (BZCYD) electrolytes with a configurational entropy of 1.22 R are prepared by doping Dy element into low-entropy BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ ( BZCY, 0.80 R). The entropy increasing strategy makes dramatically contribution to the improved chemical stability against CO 2 and H 2 O, and the relevant mechanism is clarified by the density functional theory (DFT). The BZCYD electrolyte shows stable phase composition and micro-structure after CO 2 heat treatment at 700 °C for 3 h and H 2 O treatment boiled for 3 h, while generation of impurities of BaCO 3 and Ba(OH) 2 accompanied by destroyed micro-structure are formed in the BZCY electrolyte under the same conditions. The total conductivity decay rates of BZCYD electrolyte after CO 2 heat treatment and H 2 O treatment are 44.1 % and 52.5 %, respectively, which exhibit significantly better than those of BZCY electrolyte (88 % and 74 %). According to the first-principles calculation, BZCYD electrolyte has higher CO 2 reaction energy barrier (5.21 eV) and H 2 O reaction energy barrier (7.30 eV), as well as lower CO 2 adsorption energy (−5.182 eV) and H 2 O adsorption energy (−0.742 eV), so it has better chemical stability. The peak power density of the anode-supported single cell with BZCYD electrolyte is 510 mW cm −2 at 700 °C in humid H 2 .
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2024
·
IF 5.5
Rongzhang Yang,Hao Liang,Meiran Chen,Fengqi Lu
Layer SnS 2 has been garnered significant attention for next-generation lithium-ion batteries (LIBs), due to its abundant resources and high theoretical capacity. However, the low initial Coulombic efficiency, large volume expansion and structural degradation have significantly hindered its application in LIBs. Herein, the layer Sn 0.7 (MoFeCoNiV) 0.3 S 2 nanosheets (HE3-SnS 2 ) grown on the conductive substrate carbon cloth (CC) is synthesized by one-step hydrothermal method. Multiple elements doping strategy not only increases the conformational entropy which will improve the structural stability of during cycling, but also enlarges the interlayer spacing which benefits for lithium-ion transfer. As a result, the additive-free integrated CC@HE3-SnS 2 electrode achieves a high reversible specific capacity of 1204.9 mAh g −1 with a high initial Coulombic efficiency of 94.7 % at 1C, and maintains 1011.4 mAh g −1 after 100 cycles. Specifically, the CC@HE3-SnS 2 anode exhibits excellent rate capability of 670.8 mAh g −1 at 10C. Moreover, the full cell based on CC@HE3-SnS 2 anode and commercial LiCoO 2 cathode displays a stable capacity retention of 862.7 mAh g −1 after 100 cycles at 1C. The entropy-stabilized SnS 2 -based anode with high initial Coulombic efficiency and rate capability has a competitive candidate for LIBs.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2020
·Vol. 13
·期 21
·5047
·
IF 3.057
Jun Cao,Peng Wang,Jie Shen,Qi Sun
Here, using Fe3O4@SiO2as a precursor, a novel core-shell structure magnetic Cu2+adsorbent (Fe3O4@zeolite NaA) was successfully prepared. Several methods, namely X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), Transmission electron microscope (TEM), Brunauer Emmett Teller (BET) and vibrating sample magnetometry (VSM) were used to characterize the adsorbent. A batch experiment was conducted to study the Cu2+adsorption capacity of Fe3O4@zeolite NaA at different pH values, contact time, initial Cu2+concentration and adsorbent does. It is found that the saturated adsorption capacity of Fe3O4@zeolite NaA on Cu2+is 86.54 mg/g. The adsorption isotherm analysis shows that the adsorption process of Fe3O4@zeolite NaA to Cu2+is more consistent with the Langmuir model, suggesting that it is a monolayer adsorption. Adsorption kinetics study found that the adsorption process of Fe3O4@zeolite NaA to Cu2+follows the pseudo-second kinetics model, which means that the combination of Fe3O4@zeolite NaA and Cu2+is the chemical chelating reaction. Thermodynamic analysis shows that the adsorption process of Fe3O4@zeolite NaA to Cu2+is endothermic, with increasing entropy and spontaneous in nature. The above results show that Fe3O4@zeolite NaA is a promising Cu2+adsorbent.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）