APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Hanwei Zhang,Xuri Wang,Ahmad Naveed,Tianyi Zeng,Xiaoyun Zhang,Hancheng Shi,Mingru Su,Aichun Dou,Yu Zhou,Yunjian Liu
Nickel-rich cathode materials are widely used for electronic devices because of their high capacity and rate performance. However, structural deterioration after long-term cycling leads to a significant decline in capacity and cycle life. In this work, the effects of three different cations doping on the structural stability and electrochemical performance of Ni-rich cathode materials were investigated. XRD characterization reveals that doped cation leads to broadening of the distance between Li layers and inhibiting Li + /Ni 2+ mixing arrangement. Compared with Na + and K + , the high valence Mg 2+ provides a stronger Mg-O bond, which can effectively restrain the undesired phase transition and sustain the ordered structure. Electrochemical tests demonstrate that NCA with Mg doping has better cycle stability and rate performance than Na and K. The capacity retention rate of NCA with 1% Mg doping is 87.7% after 200 cycles at 1C, and it can still provide a specific capacity of 146.8 mAh g −1 at a high rate of 5C.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2019
·
IF 3.218
Shimei Sun,Tao Liu,Quanhai Niu,Xiaolin Sun,Depeng Song,Hui Liu,Xiaoxiao Zhou,Takeo Ohsaka,Jianfei Wu
Structural degradation and side reaction in cathode materials have been regarded as the main issues that compromise the capacity and cycle stability of Ni-rich LiNi 0.8 Co 0.15 Al 0.05 O 2 . Herein, an inside-out modification method was reported to stabilize internal structure and restrain side reactions of LiNi 0.8 Co 0.15 Al 0.05 O 2 , composing of doping Mg inside the layer structure and coating Al 2 O 3 outside the cathode materials particles. Through dual protection strategies, an unprecedented capacity retention as high as 99% after 100 cycles and 95% after 250 cycles (from 178 to 168.9 mAh g −1 ) was achieved at 1.0C, which are much more superior among LiNi 0.8 Co 0.15 Al 0.05 O 2 cathodes using previously reported modification methods. X-ray diffraction results indicated that Al and Mg ions were successfully introduced into the bulk materials and exhibited excellent hexagonal structure. This work highlights that the multiple modified method is a promising strategy to enhance the cycling performance of LiNi 0.8 Co 0.15 Al 0.05 O 2 , and these enhancements can be attributed to the protection from “inside” to “outside” of LiNi 0.8 Co 0.15 Al 0.05 O 2 particles, which suppress phase transition and cation mixing inside the materials, and reduce side effects outside the particles, thus allows for rapid electron transport during the electrochemical Li + insertion/extraction reaction.
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Hanwei Zhang,Xiaoyun Zhang,Tianyi Zeng,Aichun Dou,Panpan Zhang,Mingru Su,Yu Zhou,Yunjian Liu
The application of Ni-rich ternary cathode materials is restricted by the irreversible phase transition and interfacial side reactions during long-term cycling. Herein, a LiTaO 3 coating and Ta 5+ doping strategy are simultaneously achieved by a simple solid-phase synthesis. The surface side-reaction and undesired phase transition of LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) are effectively restrained by this approach, which utilizes residual lithium to afford the coating. The NCA-LTO 3 (The modified NCA with a LiTaO 3 coating content of 3 wt%) delivers a high reversible capacity of 168.04 at 5 C (140.56 mAh g −1 for NCA), revealing the enhanced rate capability. More importantly, the cycling life could be greatly maintained after 200 cycles with a significant capacity retention of 94.1% (61.2% for NCA) at 1 C. Mechanism analysis indicates that such improvement is ascribed to the coating of conductor LiTaO 3 and doping Ta 5+ greatly promoting the Li-ion diffusion and stabilizing the interface of NCA. The study proposes a highly convenient strategy for interfacial optimization of cathode materials toward assisting the large-scale production of high-performance NCA.
研究领域:
材料科学
·
电化学
·
能源存储
·
固态化学
·
电池技术
✓ 已验证
DOI
高影响因子
Energy Technology
·
2018
·Vol. 6
·期 12
·2358-2366
·
IF 3.175
Junkai Zhao,Zhixing Wang,Jiexi Wang,Huajun Guo,Xinhai Li,Weihua Gui,Ning Chen,Guochun Yan
The rapid rise of electrode impedance and capacity decay of Ni-rich layered cathode materials during high-voltage cycling are rooted in their severe structural degradation. Here we present a feasible strategy, anchoring ∼1 % K + into the Li + sites of LiNi 0.8 Co 0.15 Al 0.05 O 2 as an excellent structural stabilizer, to overcome aforementioned issues, and the similarities and differences in terms of modification mechanism is compared with Na + . Showing difference with Na + that tends to migrate into electrolyte during high-voltage cycling, K + occupies in Li + site firmly because of its larger ionic radius and lower migrating ability, which sustainably prevent the irreversible phase transition between two hexagonal phases (H2 and H3) and impede the cation migration in highly delithiated state, thus suppressing the structural degradation. Benefiting from these merits, Li 0.99 K 0.01 Ni 0.8 Co 0.15 Al 0.05 O 2 delivers a large initial discharge capacity of 217 mAh g −1 at 0.1 C and maintains stable cycling at 1 C in a high voltage of 4.6 V (remaining 87.4 % of its initial capacity after 150 cycles). The mechanism proposed in this work, accounting for enhanced structural stability under high-voltage cycling by K + anchoring in Ni-rich cathode materials, provides a vital hint for rational designing advanced cathode materials to pursue high energy density Li-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2021
·Vol. 28
·期 2
·305-316
·
IF 2.232
Wang Hao-yang,Cheng Xue,Li Xiao-feng,Pan Ji-min,Hu Jun-hua
To probe the coupling effect of the electron and Li ion conductivities in Ni-rich layered materials (LiNi 0.8 Co 0.15 Al 0.05 O 2 , NCA), lithium lanthanum titanate (LLTO) nanofiber and carbon-coated LLTO fiber (LLTO@C) materials were introduced to polyvinylidene difluoride in a cathode. The enhancement of the conductivity was indicated by the suppressed impedance and polarization. At 1 and 5 C, the cathodes with coupling conductive paths had a more stable cycling performance. The coupling mechanism was analyzed based on the chemical state and structure evolution of NCA after cycling for 200 cycles at 5 C. In the pristine cathode, the propagation of lattice damaged regions, which consist of high-density edge-dislocation walls, destroyed the bulk integrity of NCA. In addition, the formation of a rock-salt phase on the surface of NCA caused a capacity loss. In contrast, in the LLTO@C modified cathode, although the formation of dislocation-driven atomic lattice broken regions and cation mixing occurred, they were limited to a scale of several atoms, which retarded the generation of the rock-salt phase and resulted in a pre-eminent capacity retention. Only NiO phase “pitting” occurred. A mechanism based on the synergistic transport of Li ions and electrons was proposed.
研究领域:
材料科学
·
电化学
·
能源存储技术
✓ 已验证
DOI
高影响因子
Nano Energy
·
2018
·
IF 13.12
Jun-chao Zheng,Zhuo Yang,Zhen-jiang He,Hui Tong,Wan-jing Yu,Jia-feng Zhang
LiNi 0.8 Co 0.15 Al 0.05 O 2 (LNCA) is a highly promising cathode material for lithium-ion batteries, but the low-rate capability and poor cycling stability of LNCA limit the expansibility of its commercial applications. Herein, Li 4 SiO 4 with a small amount of Al is introduced to modify LNCA by combined wet-chemical and solid-state methods and improve its rate and cycle performance. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High Resolution Transmission Electron Microscope (HRTEM), and Energy Disperse Spectroscopy (EDS) results confirm that a Li 4 SiO 4 coating layer (2–5 nm) is firmly wrapped on the LNCA surface. The modified LNCA shows surprising rate performance and excellent cycle retention. Specifically, the LNCA material coated with 3 mol% Li 4 SiO 4 displays a discharge capacity of 156.5 mAh g −1 at 10 C and exhibits a capacity retention of 88% after 100 cycles at 1 C rate(2.7–4.3 V). The excellent electrochemical performance of the LNCA@Li 4 SiO 4 is due to the incorporation of the Li 4 SiO 4 layer. This layer enhances the lithium-ion diffusion between electrode and electrolyte and suppresses the side reaction produced by direct contact between the active material and electrolyte during repeated charge–discharge cycles. All these findings indicate the high potential of this material for application in advanced lithium-ion batteries.
研究领域:
材料科学
·
电化学
·
储能
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Su Wang,Qifang Sun,Chen Li,Dongge Wang,Yue Ma,Hongzhou Zhang,Xixi Shi,Lianqi Zhang,Dawei Song
Given the high combustion or explosion potential of liquid electrolyte, polymer electrolytes have attracted intensive attention due to high safety, compatible interface and flexible processability. However, the related low ionic mobility remains an issue for related wide application. Herein, a crosslinked polymer electrolyte (abbreviated as PMEP) comprising abundant oxygen-contained groups (C-O-C/C=O) is developed. With the crosslinking agent of ethoxylated trimethylolpropane triacrylate (ETPTA), a high transference number ( t Li + =0.69) is obtained since C-O/C=O are conducive to the transfer of Li ions. Specifically, C=O group exists in individual monomers in order to be applicable to high voltage cathode, therefore, a criss-cross network containing abundant sites conducive to ion transport is constructed and rapid ion transfer as well as enhanced mechanical strength can be realized even in high potential system. With the coordination effect of C-O and C=O, PMEP exhibits rapid Li ion transfer and a wide electrochemical stability window of 5.1 V. As for Li//Li symmetrical cell, a stable voltage profile with slight polarization of 60 mV is displayed for over 550 h at 1 mA cm −2 . After assembled with LiNi 0.8 Co 0.15 Al 0.05 O 2 cathode, a high discharge specific capacity of 190.6 mAh g −1 is delivered and the capacity retention reaches 86 % at 0.1C for 100 cycles. This work provides a promising method for designing high-performance polymer electrolytes for lithium metal batteries.
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
危险品化学品经营许可证（带存储）