ACS Applied Energy Materials
·
2020
·
IF 4.473
Chuan-Wei Wang,Yao Zhou,Jin-Hai You,Jian-De Chen,Zheng Zhang,Shao-Jian Zhang,Chen-Guang Shi,Wei-Dong Zhang,Ming-Hua Zou,Yang Yu,Jun-Tao Li,Lei-Ying Zeng,Ling Huang,Shi-Gang Sun
The LiCoO2 (LCO) cathode has been widely used in material markets, especially in conventional lithium ion batteries, due to its stable electrochemical performance. Increasing the working cutoff potential represents an efficient pathway to boost the capacity of LCO batteries; however, high working potentials usually induce severe Co3+ dissolution and extensive growth of solid electrolyte interphase (SEI) layer, leading to rapid degradation of the electrochemical performance. In this work, a high voltage cathode is prepared by the encapsulation of aluminum (Al)-doped LiCoO2 in a continuous Li4Ti5O12 (LTO) layer using a high-speed solid-phase coating method. The chemical composition evolution of the coating layer during the cycling process was characterized and evaluated through in situ XRD, XPS, and XAS analyses. The precipitation of aluminum fluoride (AlF3) at the defective sites of the LTO coating layer in the initial charge–discharge cycles effectively was found to fortify the structural integrity of the coating layer and prevent the etching of the LCO from undesirable side reactions with the liquid electrolyte. The modified LCO demonstrated an excellent capacity retention of 89.9% after 100 cycles at 0.2 C. The high-speed solid-phase coating method established in this study could be scaled up straightforwardly, providing a highly commercializable approach for large-scale production of stable high-voltage LCO cathode materials.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Bei Hu,Fushan Geng,Ming Shen,Chong Zhao,Qing Qiu,Yang Lin,Changxin Chen,Wen Wen,Shun Zheng,Xiaoshi Hu,Chao Li,Bingwen Hu
LiCoO 2 , as a domain cathode material of Li-ion batteries, faces a great deal of challenges due to the limited cycling stability at high voltage (>4.35 V vs. Li/Li + ). These issues are tentatively addressed here by a multifunctional self-stabilization modification strategy, involving trace Mg bulk doping, surface gradient Ti doping and BaTiO 3 dot coating in LiCoO 2 . The multifunctional synergy is verified to overcome the detrimental irreversible phase transition and the growth of impedance of LiCoO 2 cycling at 4.6 V. By using soft X-ray absorption spectroscopy (sXAS) and electron paramagnetic resonance (EPR) techniques, we also elucidate that Ti surface gradient doping can reinforce the structure rigidity of the particles while significantly attenuates the irreversible oxygen redox at high voltage. All these strategies promote the prolonged cyclic performance of LiCoO 2 under 4.6 V high-voltage through different mechanism. This elaborate investigation provides an instructive contribution in the advancement of high-voltage LiCoO 2 .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Teng Li,Ruizi Wang,Zikang Cai,Wenzhe Liu,Jiwei Song,Xixi Wu,Chunyan Cao,Liangjie Yuan
To date, LiCoO 2 has received extensive attention as a cathode material because of its unique characteristics. To satisfy the strong demand for high energy density , the cut-off voltage of LiCoO 2 is continuously increased. However, the structural instability of LiCoO 2 at a high cut-off voltage leads to capacity decay and many safety issues, which hinder further application of LiCoO 2 . Herein, YPO 4 is used to achieve a better electrochemical performance for LiCoO 2 at 4.55 V. In the synthesis process, YPO 4 is transformed into the Li 3 PO 4 and Y 2 O 3 phases, which are basically uniformly incorporated into the particle and form a composite with LiCoO 2 . Owing to the synergistic modification of Li 3 PO 4 and Y 2 O 3 phases, YPO 4 -modified LiCoO 2 materials show enhanced structural stability and excellent cycling performance. Particularly, 1.5% YPO 4 modified LiCoO 2 not only exhibits a reversible discharge capacity of 171.6 mAh g −1 over 500 cycles with 91.7% capacity retention, but also delivers a capacity of 144.5 mAh g −1 at 5 C (1 C = 274 mAh g −1 ). This work suggests that using rare-earth metal phosphates can be an effective strategy to improve the cycling performance of LiCoO 2 at 4.55 V.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2013
·
IF 3.777
Qin Hao,Caixia Xu,Suzhen Jia,Xiaoyun Zhao
Fe 2 O 3 nanoparticles are employed as a coating material to optimize the electrochemical performance of LiCoO 2 at high voltage. When the current rate is 1 C with the cutoff potential at 4.5 V, the 5 wt.% Fe 2 O 3 -coated LiCoO 2 delivers an initial capacity of 168.7 mAh g −1 . More importantly, its capacity retention after 50 cycles reaches up to 92.6%, whereas the value for pristine LiCoO 2 is only 58.5%. The electrochemistry impedance spectroscopy analysis demonstrates that Fe 2 O 3 coating plays an important role in decreasing the charge transfer resistance of cell. Compared with the performance of the Fe 2 O 3 -mixed and Fe-doped LiCoO 2 samples, it is found that the role of Fe 2 O 3 coating is unique, which may change the characteristic of the surface of LiCoO 2 particles. This technique may provide an effective and convenient way for optimizing other electrode materials .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Wei-Chen Zheng,Jin-Xia Lin,Hui Chen,Shi-Shi Liu,Chen-Guang Shi,Ling Huang,Shi-Gang Sun
Ni-rich layered oxides are considered ideal positive electrode materials for next-generation state-of-the-art Li-based batteries owing to their high energy densities. However, the structural degradation of Ni-rich positive electrodes and electrolyte decomposition presents significant challenges, particularly at high cut-off voltages. Herein, we report a novel electrolyte consisting of fluorinated solvents that enables the long lifespan of a Li||LiNiO 2 cell with a cut-off voltage of up to 4.5 V. The Li||LiNiO 2 cell retains 93.8% of its initial capacity after 200 cycles. The cycling stability was ascribed to the fluorinated solvents dominating the first structural shell of Li + and deriving a robust cathode-electrolyte interphase (CEI) on the positive electrode. Compared to commercial electrolytes, the fluorinated electrolyte inhibits the structural degradation, stress corrosion cracking, and interphase side reactions of the LiNiO 2 electrode. On the Li negative electrode side, ideal Li plating/stripping and the inhibition of the attack of Ni 2+ are achieved. Furthermore, the 4.5 V-Li||LiNiO 2 cell exhibited a capacity retention of 80.2% after 100 cycles, even under extremely fast-charging conditions.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Yawei Chen,Fanyang Huang,Miao Xie,Yehu Han,Wanxia Li,Yulin Jie,Xingbao Zhu,Tao Cheng,Ruiguo Cao,Shuhong Jiao
High-voltage Li metal batteries (LMBs) based on ether electrolytes hold potential for achieving high energy densities exceeding 500 Wh kg–1, but face challenges with electrolyte oxidative stability, particularly concerning aluminum (Al) current collector corrosion. However, the specific chemistry behind Al corrosion and its effect on electrolyte components remains unexplored. Here, our study delves into Al corrosion in the representative LiFSI-DME electrolyte system, revealing that low-concentration electrolytes exacerbate Al current collector corrosion and solvent decomposition. In contrast, high-concentration electrolytes mitigate these issues, enhancing long-term stability. Remarkably, LiFSI-0.7DME electrolyte demonstrates exceptional stability with up to 1000 cycles at high voltage without significant capacity decay. These findings offer crucial insights into Al corrosion mechanisms in ether-based electrolytes, advancing our comprehension of high-voltage LMBs and facilitating their development for practical applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Liu Gao,Fujie Li,Guangrong Zeng,Xin Jin,Zhenyou Li,Chao Wang
Elevating the charging cut-off voltage is an effective strategy to increase the energy density of LiCoO 2 . However, unstable interfacial structures and unfavorable phase transitions in bulk are inevitably triggered during deep de-lithiation at high voltage. Herein, an integrated surface-to-bulk Ti-modification strategy is applied to LiCoO 2 , enabling uniform Li 2 TiO 3 coating on the surface and gradient Ti-doping toward the structural bulk. The resultant Ti-modified LiCoO 2 (T-LCO) electrode can be stably cycled up to 4.6 V, providing a high-rate capability of 137 mAh g −1 at 5C and a long-life stability with 80.5% capacity retention after 400 cycles at 1C, far outperforming the unmodified LiCoO 2 electrode with only 50.7% capacity retention. In situ X-ray diffraction characterization and density functional theory calculation reveal that the synergistic modification of T-LCO enhances Li + diffusion, facilitates the construction of high-quality cathode/electrolyte interphase, reduces the phase transition from O3 to H1-3 and Co3d/O2p band overlap, and restrains layer-to-spinel phase distortion, thus improving structural stability at 4.6 V. This work presents a “two birds one step” strategy to enhance the cycling stability and achievable capacity of high-voltage LiCoO 2 for developing high energy density lithium-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
Small
·
2024
·
IF 13
Kai Yang,Keding Chen,Xingdi Zhang,Shuyu Gao,Jichang Sun,Jin Gong,Jinchao Chai,Yun Zheng,Zhihong Liu,Honghua Wang
Polyvinylidene fluoride (PVDF) has unique electrochemical oxidation resistance and is the only binder for high-voltage cathode materials in the battery industry for a long time. However, PVDF still has some drawbacks, such as environmental limitations on fluorine, strict requirements for environmental humidity, weak adhesion, and poor lithium ion conductivity. Herein, the long-standing issues associated with high-voltage lithium cobalt oxide (LiCoO 2 ; LCO) are successfully addressed by incorporating phenolphthalein polyetherketone (PEK-C) and phenolphthalein polyethersulfone (PES-C) as binder materials. These binders have unexpected electrochemical oxidation resistance and robustness adhesion, ensure uniform coverage on the surface of LCO, and establish an effective and fast ion-conductive CEI/binder composite layer. By leveraging these favorable characteristics, electrodes based on polyarylether binders demonstrate significantly better cycling and rate performance than their counterparts using traditional PVDF binders. The fast ion-conductive CEI/binder composite layer effectively mitigates adverse reactions at the cathode–electrolyte interface. As anticipated, batteries utilizing phenolphthalein polyarylether binders exhibit capacity retention rates of 88.92% and 80.4% after 200 and 500 cycles at 4.5 and 4.6 V, respectively. The application of binders, such as polyarylether binders, offers a straightforward and inspiring approach for designing high-energy-density battery materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Yu Peng,Jiawei Chen,Gaopan Liu,Yue Yin,Xiaoli Fang,Yonggang Wang,Xiaoli Dong,Yongyao Xia
Lithium metal batteries (LMBs) with Li metal anodes and high-voltage LiCoO 2 (LCO) cathodes offer high energy density but face challenges such as Li dendrite growth and LCO structure degradation, which primarily arises from the electrolyte's inability to form a stable interphase. Herein, a dual-additive optimized carbonate-based electrolyte is developed, incorporating tetraethylammonium nitrate (TEANO 3 ) and lithium difluorobis(oxalato) phosphate (LiDFBOP) as regulators. LiDFBOP enhances interfacial stability and compactness, while TEANO 3 facilitates Li + transport and suppresses excessive decomposition of LiDFBOP. The synergistic effect of TEANO 3 and LiDFBOP establishes robust, high ion-conductive solid electrolyte interphase (SEI) and cathode–electrolyte interphase (CEI) enriched with P- and N-containing inorganic compounds (including LiN x O y and P-O/P-F species), enabling dense Li deposition and stable cycling of LCO under a high cut-off voltage of 4.5 V. The optimized electrolyte enables Li||LCO full cells with a high capacity retention of 84% even with high-mass-loading LCO cathode (3.5 mAh cm −2 ) and limited Li (N/P = 2). This work demonstrates a straightforward electrolyte design strategy for optimizing SEI and CEI, advancing the practical deployment of LMBs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 6
·期 4
·1496-1503
·
IF 8.867
Xiangdong Ma,Xiaoxi Zuo,Jinhua Wu,Xiao Deng,Xin Xiao,Jiansheng Liu,Junmin Nan
A new polyethylene (PE)-supported ultra-thin blended polymer electrolyte based on polyvinylidene fluoride/hydroxyethyl cellulose (PVDF/HEC) was prepared by a simple dipping method for 5 V high voltage lithium-ion batteries (LIBs). The performances of the prepared membranes and the resulting GPEs were investigated by scanning electron microscopy, electrochemical impedance spectroscopy, linear potential sweep voltammetry, and charge–discharge cycling. The effects of the ratio of PVDF to HEC on the performance of the composite separator were further discussed. It was found that PE-supported polymer separators (PVDF : HEC = 3 : 1, by weight) present the best mechanical, thermal and wettability performance. The ionic conductivity of this GPE is 0.78 mS cm−1, which is much higher than that of PE separators (0.39 mS cm−1) at room temperature. The electrochemical stability of this GPE can reach up to 5.25 V (vs. Li/Li+). A LiNi0.5Mn1.5O4 cathode with this GPE exhibits a superior cycling stability and rate performance at room temperature. This suggests that the polyethylene (PE)-supported ultra-thin blended polymer electrolyte can be used for 5 V LIBs due to its good performance, low cost and strong operability.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2025
·
IF 14.9
Zhen Wang,Jun-Ke Liu,Li Deng,Jian Liu,Zhi-Liang Jin,Yu-Xi Luo,Guo-Dong Bai,Wen-Jing Sun,Gao-Yang Bai,Jing-Yi Lin,Zu-Wei Yin,Yao Zhou,Jun-Tao Li
Extending the charging voltage of LiCoO 2 (LCO) is an ongoing and promising approach to increase its energy density. However, the main challenge of the approach lies in the insuperable cathodic interfacial processes at high voltage, which leads to rapid failure both in the performance and structure of the LCO cathode. Herein, a Li 2 CO 3 -based additive was prepared by a simple sand-milling method, enabling a low electrochemical decomposition voltage <4.6 V from commonly >4.8 V, stabilizing the interface of the LCO cathode at 4.6 V. The decomposition of Li 2 CO 3 provides extra Li + and CO 2 to supplement the Li consumption required in the initial irreversible interfacial reactions and rapidly form a uniform and stable cathode electrolyte interphase layer (less organic and more inorganic components) on the LCO cathode by reducing CO 2 . Thus, the phase transformation and the emergence of high-valent Co ions on the surface of LCO at 4.6 V high voltage were inhibited. Thanks to this, with 2% Li 2 CO 3 -based additive, the capacity retention of commercial LCO at a high voltage of 4.6 V at 0.5 C for 100 cycles was improved from 59.3% to 79.3%. This work improves the high-voltage stability of LCO and provides a new idea for realizing the high-voltage operation of 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
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Zhaoyu Sun,Hebing Zhou,Xuehuan Luo,Yanxia Che,Weishan Li,Mengqing Xu
A novel electrolyte additive designed as a cathode interface formation enhancer for high voltage lithium-ion battery (LIB) systems is investigated. Lithium 4-benzonitrile trimethyl borate (LBTB) is synthesized by a two-step reaction, and the results show that the cycling performance of Li/LiCoO 2 cell at 4.4 V is significantly improved from 15.08% to 73.21% by adding 2.0 wt% of LBTB to the electrolyte (1.0 M LiPF 6 in EC/DEC/EMC = 3/2/5, wt.%). A combination of electrochemical methods , ex-situ spectroscopy characterization techniques and computational calculations are employed to investigate the mechanisms of action for this additive. Cyclic voltammograms indicate the additive is preferably oxidized on the LiCoO 2 surface prior to the electrolyte oxidation and results in a more stable and robust passivation layer than the electrolyte alone. Computational calculations support the observed sacrificial oxidation of LBTB prior to the electrolyte solvents decomposition. The CEI formed by LBTB decomposition mitigates the dissolution of transition metal and subsequently improves the cycling stability of the LiCoO 2 cathodes at high voltages. Surface characterization techniques reveal the presence of -B-O- products derived from LBTB decomposition on the surface of the LCO cathode.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）