NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 7
·4824-4834
·
IF 3.201
Guo Ye,Qianjie Zhou,Danqin Li,Yinxiu Zuo,Xuemin Duan,Weiqiang Zhou,Jingkun Xu
Freestanding flexible capacitive materials are ideal for use in bendable electronic devices. However, it is difficult to prepare pure PEDOT films in a freestanding state by chemical and electrochemical methods. Here, we used a simple strategy of introducing alkoxy, ether, ester, and amide chains for bridging two EDOT units to form precursors, which could then be electrodeposited readily to produce freestanding and flexible films. The precursor with the amide group was suitable for obtaining higher-quality films with improved thermal stability, mechanical properties, and capacitive performance. In addition, the asymmetric PBEDTA//PEDOT capacitors exhibited a capacitance retention rate of 98.5% after 5000 cycles, which is higher than those of PBEDTH//PEDOT (92.7%), PBEDTG//PEDOT (80.5%), and PBEDTE//PEDOT (86.8%) capacitors. This result indicates that the polymer films and, in particular, the PBEDTA films, are suitable for use in flexible supercapacitors.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2024
·
IF 5.5
Mohamed M. Abdelaal,Mohammad Alkhedher
The energy storage market necessitates an increase in the specific capacity of battery materials, particularly cathodes, to meet growing demands. Manganese (Mn) substitution of lithium iron phosphate (LFP) cathodes presents a promising avenue, offering high specific capacity and operability at elevated voltages. However, during cycling, the dissolution of Fe/Mn ions into the electrolyte leads to capacity fading. In this study, we enhance the specific capacity of LFP by Mn substitution in the iron position at various ratios (0.1, 0.2, 0.3, and 0.4). LiFe 0.6 Mn 0.4 PO 4 exhibits the highest capacity of 159.1 mAh g -1 at 0.1C with an initial Coulombic efficiency of 97.9 %. This improvement stems from an enhanced lithium diffusion coefficient, increasing from 1.86 × 10 –14 cm 2 s -1 for pristine LFP to 2.46 × 10 –12 cm 2 s -1 for LiFe 0.6 Mn 0.4 PO 4 . However, LiFe 0.6 Mn 0.4 PO 4 demonstrates the poorest capacity retention among the substituted samples, reaching 78.4 % over 100 cycles due to severe Fe/Mn ion dissolution. To address this issue, we coat Mn-substituted LFP with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and lithiated Nafion (LN) polymer, which offer high electronic and lithium-ion conductivity, respectively. This coating layer enhances the capacity retention of LiFe 0.6 Mn 0.4 PO 4 to 90.1 % at 0.2C after 100 cycles, effectively mitigating active material loss during charge-discharge processes. This study demonstrates that PEDOT:PSS-LN can improve the electronic and ionic conductivity of cathode materials and maintain high capacity retention during cycling.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 35
·12337-12344
·
IF 4.099
Xia Wu,Shi-Xi Zhao,Lü-Qiang Yu,Jin-Lin Yang,Ce-Wen Nan
Based on the existing calculation reports, sulfur doping is an effective approach to alleviate the structure collapse of Li2MnSiO4 during cycling. Herein, we investigate the feasibility and limitations of S doping in Li2MnSiO4 by experiment. In our work, the solid solubility of S is confirmed and exceeding the threshold results in MnS impurity. The existence state and site of the S element in a Li2MnSiO4 crystal structure is also confirmed. It is found that S doping significantly improves the structural reversibility and cycling stability. Compared with a pristine sample, a 1mol% S doped sample exhibits a much higher initial coulombic efficiency (88.3%), excellent capacity retention (98% at 10th cycles for instance) and enhanced rate performance. Moreover, the 1mol% S doped sample can retain a discharge capacity of 137 mA h g−1 after 30 cycles while the pristine sample only has 61.6 mA h g−1. This study confirms the effectivity of S doping in suppressing the structural distortion in Li2MnSiO4.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Hao Chen,Li Xiao,Pengcheng Liu,Han Chen,Zhimei Xia,Longgang Ye,Yujie Hu
Herein, a strategy is presented for improving the electrochemical performance of a LiNixCoyMn1–x–yO2 layered oxide involving the coating of rock salt-type LiTiO2 on the surface via a hydrothermal method followed by a calcination process. A thickness of approximately 10 nm of LiTiO2 coated on the surface of LiNi0.5Co0.2Mn0.3O2 (NCM523) has been achieved, and the optimal molar ratio (LiTiO2/NCM523) is found to be 1.0 mol %. The LiTiO2@LiNi0.5Co0.2Mn0.3O2 when used as a cathode material exhibits not only a higher capacity retention but also a more enhanced rate performance in comparison with that of pristine NCM523. The LiTiO2 layer protects the NCM523 active particles from being eroded by the electrolyte and reduces the volume change of the electrode active particles before and after lithium-ion intercalation/deintercalation during cycling. These new findings contribute toward the design of a stable structured nickel-based cathode material for lithium-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2024
·Vol. 171
·期 8
·080526
·
IF 3.1
Xiaoning Li,Mengmeng Liu,Wenjuan Zhang,Yanli Zhang,Jiakun Zhou,Wenzhang Zhou,Naixin Wang,Weiwei Xu,Kehua Dai
O3-type NaNi0.4Fe0.2Mn0.4O2 cathode materials are structurally stable and have a high nickel content, allowing for stable high-capacity output. However, their performance needs further improvement. First, we investigated the effects of different sodium contents on the structure, morphology, and electrochemical performance of NaxNi0.4Fe0.2Mn0.4O2(x = 0.85, 0.9, 0.95, 1, 1.05) materials. The Na0.9Ni0.4Fe0.2Mn0.4O2 material exhibited initial discharge specific capacities of 148.11 and 181.80 mAh·g−1 at voltage ranges of 2–4.1 V and 2–4.2 V, respectively. To further optimize the cycling performance of the material, we doped NaNi0.4Fe0.2Mn0.4O2 with different calcium contents. Ca2+ doping significantly enhanced the electrochemical performance of the material. Subsequently, we synthesized Na0.96Ca0.02(NMF)0.95Zn0.05O2, and the dual-doped NMF-Ca0.02Zn0.05 maintains approximately 80% capacity retention at 1–4.05 V, and around 70% as the cut-off voltage increases to 4.15 V in full cells.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 27
·9268-9273
·
IF 4.174
Lu He,Chuan Tan,Chuanchao Sheng,Yuanzhao Chen,Fengjiao Yu,Yuhui Chen
FeOOH is one of the earth abundant and high-capacity anode materials for lithium-ion batteries (LIBs), but faces problems of inevitable structure collapse and thus poor capacity retention. Herein, we report a composite of β-FeOOH/Ti3C2Tx MXene sandwich by an intercalation of β-FeOOH nanorods within single-layer Ti3C2Tx MXene flakes. After 100 cycles, the β-FeOOH/Ti3C2Tx composite retains a capacity of 937.5 mA h g−1 at 200 mA g−1, and 671.4 mA h g−1 at 1 A g−1. The composite as an anode in LIB delivers improved cyclability and better high-rate performance compared to pristine β-FeOOH, which result from the excellent conductivity of single-layer MXene, facilitating mass transport by the sandwich structure. This work provides a strategy for the design of electrodes, particularly in Na-ion and K-ion batteries, which involve active materials that experience volume change and structural damage during cycling.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-12
·
IF 16.6
Wu Lichen,Fu Hongwei,Li Shu,Zhu Jian,Zhou Jiang,Rao Apparao M.,Cha Limei,Guo Kunkun,Wen Shuangchun,Lu Bingan
The crystal phase structure of cathode material plays an important role in the cell performance. During cycling, the cathode material experiences immense stress due to phase transformation, resulting in capacity degradation. Here, we show phase-engineered VO 2 as an improved potassium-ion battery cathode; specifically, the amorphous VO 2 exhibits superior K storage ability, while the crystalline M phase VO 2 cannot even store K + ions stably. In contrast to other crystal phases, amorphous VO 2 exhibits alleviated volume variation and improved electrochemical performance, leading to a maximum capacity of 111 mAh g −1 delivered at 20 mA g −1 and over 8 months of operation with good coulombic efficiency at 100 mA g −1 . The capacity retention reaches 80% after 8500 cycles at 500 mA g −1 . This work illustrates the effectiveness and superiority of phase engineering and provides meaningful insights into material optimization for rechargeable batteries.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Energy Materials
·
2022
·
IF 6.959
Hanwu Luo,Siqing Qi,Xin-Yu Fan,Fang-Di Ji,Yi-Hu Feng,Duo Si,Da-Wei Wang,Mengting Liu,Xiaogang Han,Peng-Fei Wang
Lithium-ion batteries are widely used in electric vehicles and smart grids to facilitate fast and stable energy storage at different temperatures. However, the decreased Li+ diffusion and poor electronic conductivity of commercial cathode materials inevitably lead to irreversible energy degradation at low temperature. Herein, we tame the relationship between diffusion and temperature of spinel LiNi0.5Mn1.5O4 cathode by incorporating Co element into transition-metal sites. The Co element into the LiNi0.5Mn1.5O4 lattice effectively improves the diffusion properties of lithium ions, enhances its electronic conductivity, and prevents the dissolution of Mn. Therefore, LiNi0.4Co0.1Mn1.5O4 could deliver a capacity retention of 93.89% at 1 C after 200 cycles at 25 °C. Even at −20 °C, it delivers 88.43% of its room-temperature capacity. Moreover, the assembled LiNi0.4Co0.1Mn1.5O4/graphite and LiNi0.4Co0.1Mn1.5O4/Li4Ti5O12 full cells both show a capacity retention of 98.03 and 86.61% at 1 C after 100 cycles, respectively. In particular, the LiNi0.4Co0.1Mn1.5O4/Li4Ti5O12 full battery still exhibits a discharge capacity of 116.9 mA h g–1 at −20 °C, reaching 90.24% of its room-temperature capacity. These results not only pave the way for improving the electrochemical performance of 5 V-based cathode materials but also provide insightful guidance for their commercial applications at low temperature.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Nature Sustainability
·
2024
·
IF 25.7
Wang Junxiong,Ji Haocheng,Li Junfeng,Liang Zheng,Chen Wen,Zhu Yanfei,Ji Guanjun,Shi Ruyu,Zhou Guangmin,Cheng Hui-Ming
Direct recycling is a promising route for the sustainable management of end-of-life spent cathodes. However, its practical implementation is greatly restricted as most existing methods require heating or high-pressure conditions during the lithiation step to overcome the thermodynamic obstacles and realize lithium replenishment. In this study, we explored a strategy to realize spontaneous lithiation via simple solid–liquid mixing at ambient conditions. The thermodynamic barrier of the lithiation reaction was reduced by self-adsorbed amyloxylithium, which can spontaneously adsorb on the surface of degraded cathode particles without an external driving force. This strategy can regenerate both laboratory-dismantled LiNi 0.6 Co 0.2 Mn 0.2 O 2 from 10 Ah pouch cells and industrial-dismantled LiNi 0.5 Co 0.2 Mn 0.3 O 2 black mass. The capacity retention rate of a 1 Ah pouch cell assembled using regenerated LiNi 0.5 Co 0.2 Mn 0.3 O 2 as cathode material was 80.5% after 500 cycles. The proposed strategy has big economic advantages over conventional pyro- and hydrometallurgical methods, as evidenced by the techno-economic analysis, accompanied by obvious environmental benefits, as evidenced by reduced CO 2 emissions. This work provides a viable approach for the direct recycling of spent cathode material, improving the circularity of the battery industry.
研究领域:
材料科学
·
能源技术
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Chinese Physics B
·
2023
·Vol. 32
·期 8
·088201
·
IF 1.7
Fuliang Guo,Jiaze Lu,Meihua Su,Yue Chen,Jieyun Zheng,Liang Yin,Hong Li
The structural transformations, oxygen releasing and side reactions with electrolytes on the surface are considered as the main causes of the performance degradation of Li-rich layered oxides (LROs) cathodes in Li-ion batteries. Thus, stabilizing the surfaces of LROs is the key to realize their practical application in high energy density Li-ion batteries. Surface coating is regarded as one of the most effective strategies for high voltage cathodes. The ideal coating materials should prevent cathodes from electrolyte corrosion and possess both electronic and Li-ionic conductivities simultaneously. However, commonly reported coating materials are unable to balance these functions well. Herein, a new type of coating material, La2CuO4 was introduced to mitigate the surface issues of LROs for the first time, due to its superb electronic conductivity (26–35 mS⋅cm−1) and lithium-ionic diffusion coefficient (10−12–10−13 cm2⋅s−1). After coating with the La2CuO4, the capacity retention of Li1.2Ni0.54Co0.13Mn0.13O2 cathode was increased to 85.9% (compared to 79.3% of uncoated cathode) after 150 cycles in the voltage range of 2.0–4.8 V. In addition, only negligible degradations on the deliverable capacity and rate capability were observed.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Advanced Energy Materials
·
2018
·Vol. 8
·期 12
·1702889
·
IF 21.875
Wei Chen,Tianyu Lei,Tao Qian,Weiqiang Lv,Weidong He,Chunyang Wu,Xuejun Liu,Jie Liu,Bo Chen,Chenglin Yan,Jie Xiong
As one of the important ingredients in lithium-sulfur battery, the binders greatly impact the battery performance. However, conventional binders have intrinsic drawbacks such as poor capability of absorbing hydrophilic lithium polysulfides, resulting in severe capacity decay. This study reports a new type of binder by polymerization of hydrophilic poly(ethylene glycol) diglycidyl ether with polyethylenimine, which enables strongly anchoring polysulfides for high-performance lithium sulfur batteries, demonstrating remarkable improvement in both mechanical performance for standing up to 100 g weight and an excellent capacity retention of 72% over 400 cycles at 1.5 C. Importantly, in situ micro-Raman investigation verifies the effectively reduced polysulfides shuttling from sulfur cathode to lithium anode, which shows the greatly suppressed shuttle effect by the polar-functional binder. X-ray photoelectron spectroscopy analysis into the discharge intermediates upon battery cycling reveals that the hydrophilic binder endows the sulfur electrodes with multidimensional Li-O, Li-N, and S-O interactions with sulfur species to effectively mitigate lithium polysulfide dissolution, which is theoretically confirmed by density-functional theory calculations.
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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Yike Xiong,Shenghong Chang,Yunjiao Li,Junchao Zheng,Xugang Ren,Zhouliang Tan,Xiaoming Xi,Jiachao Yang,Shuaiwei Liu,Shan Wang
YPO 4 modified Ni-rich cathode materials LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) are favourably synthesized via a traditional high temperature solid-state method. Herein, the structure as well as thermal stability are promoted through the synergistic effect of Y 3+ doping and LiYO 2 - Li 3 PO 4 dual surface modification. The results turn out to solve the lattice structure defects, Li + migration issue and, most of all, residual lithium issue. The most effective sample exhibits extraordinary 96.35% capacity retention with the initial specific discharge capacity of 186.1 mAh g −1 at 4.4 V cut-off voltage, 1 C, 25 ℃ after 100 cycles. Moreover, after 0.5, 1, 2, 4, 8 C cycling periods, at the time when the rate back to 0.5 C, the capacity of the YPO 4 modified samples remain almost the same as the first 0.5 C cycles. It obviously can be seen that the YPO 4 modification in this work is no doubt a promising strategy to optimize the manufacturing of cathode materials in Li-ion batteries field.
研究领域:
材料科学
·
电化学
✓ 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）