Energy Technology
·
2019
·Vol. 7
·期 4
·1800981
·
IF 3.163
Bangwei Deng,Hao Wang,Xiang Li,Yan Ding,Daming Sun,Jun Ma,Mianzhong Chen,Tao Chen,Feng Gao,Meizhen Qu,Gongchang Peng
Tris(trimethylsilyl)phosphite (TMSPi) has been reported to be an excellent electrolyte additive. However, scarce reports exist on the effect of the charge cutoff potential on the cyclic stability using high-performance LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622)–mesocarbon microbead (MCMB) full cells. Herein, a high-loading and repeatable NCM622–MCMB coin-type full cell is successfully prepared, and the role of TMSPi on such a full cell at charge cutoff potentials of 4.25 and 4.45 V is studied. Theoretical calculations and detailed analyses reveal that it is oxidized in the first charging process due to its unsaturated P—O bonds, thus forming a stable P—O—F-rich cathode electrolyte interphase and preventing severe decomposition of the electrolyte over NCM622 during long-term cycling. In addition, the P—O and Si—O bonds of TMSPi both display HF-scavenging ability. Moreover, TMSPi may react directly with the LiPF 6 -based electrolyte to form some intermediate products that can be reduced on the MCMB electrode, thereby modifying the solid electrolyte interphase and improving the stability of MCMB during lithium intercalation.
研究领域:
电化学
·
材料科学
·
能源存储
·
锂离子电池
·
界面化学
·
电极材料
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Jingxiong Gao,Songyi Han,Haiming Hua,Jie Wu,Jing Zeng,Yuanyu Sun,Weiping Tang,Shuling Liu,Jinbao Zhao
To optimize the electrochemical behavior of NCM-based high-energy lithium-ion batteries (LIBs) in wide temperature ranges, Phenyl trifluoromethane sulfonate (PTM) is demonstrated as the novel electrolyte additive to enhance the electrochemical behavior of LiNi 0·6 Co 0·2 Mn 0·2 O 2 /graphite cells at 25 °C, −20 °C and 45 °C. The cells with 1.0 wt% PTM-containing electrolyte deliver 80.6% capacity retention after 350 cycles at 25 °C, 73.4% after 100 cycles at −20 °C, and 82.6% after 300 cycles at 45 °C, which are significantly higher than that in standard electrolyte (STD), corresponding to 36.4% at 25 °C, 40.3% at −20 °C, and failure at 45 °C, respectively. According to density functional theory (DFT) simulations and quantitative calculations, the PTM preferentially reduces on the anode and oxidizes on the cathode to participate in the formation of solid electrolyte interphase (SEI) films. In addition, the scanning electron microscopy (SEM), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and other analysis suggest that the formed SEI films are thinner and more stable for the electrolyte containing PTM, and the formed SEI films effectively control the decomposition of carbonate-based electrolytes and greatly decrease the increased resistance during the cycle.
研究领域:
电化学
·
材料科学
·
能源存储
·
锂电池技术
·
界面化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Xinhe Yang,Zicheng Zuo,Haiyan Wang,Quanbin Chen,Hui Zhang,Zhenlei Huang,Borong Wu,Henghui Zhou
A one-step synthesis method is developed to prepare the Li[Ni 0.5 Co 0.2 Mn 0.3 ]O 2 (NCM 523) cathode with uniform tungsten-coating layer for lithium-ion battery . Such modified material shows similar properties with the bare NCM 523 in terms of the primary particles, secondary structure , and specific capacity. With W coating layer , the NCM 523 gives remarkable improvement in the long-term capacity retention in the half-cell testing, which is sharply inconsistent with the result from the full-battery tests, indicating a contradiction between the half-cell and full-battery tests in some case. After further investigations, such conflict between the half-cell and full-cell tests in evaluating the W-coating strategy is attributed to the dissolution of Li 2 WO 4 layer in the electrolyte, which probably destroys the solid electrolyte interface (SEI) on the graphite anode and irreversibly consumes the active lithium ions for renovating SEI in full-cell testing. These results will benefit researchers in the area of lithium-ion batteries to fully understand the differences between the half-cell and full-cell testing, and develop the effective strategies for cathode modifications.
研究领域:
电化学
·
材料科学
·
能源存储
·
电池技术
·
表面改性
·
固态离子学
✓ 已验证
DOI
高影响因子
Energy & Environmental Materials
·
2022
·Vol. 6
·期 3
·e12351
·
IF 13.443
Qiyu Wang,Xiangqun Xu,Bo Hong,Maohui Bai,Jie Li,Zhian Zhang,Yanqing Lai
Quasi-solid-state lithium metal battery is a promising candidate for next generation high energy density and high safety power supply. Despite intensive efforts on electrolytes, uncontrolled interfacial reactions on lithium with electrolyte and patchy interfacial contacts still hinder its practical process. Herein, we bring in rationally designed F contained groups into polymer skeleton via in-situ gelation for the first time to establish quasi-solid-state battery. This method achieves a capacity retention of 90% after 1000 cycles at 0.5C with LiFePO 4 cathodes. The interface constructed by polymer skeleton and reaction with –CF 3 lead to the predicted solid electrolyte interface species with high stability. Furthermore, we optimize molecular reactivity and interface stability with regulating F contained end groups in the polymer. Comparisons on different structures reveal that high performance solid stable lithium metal batteries rely on chemical modification as well as stable polymer skeleton, which is more critical to construct robust and steady SEI with uniform lithium deposition. New approach with functional groups regulation proposes a more stable cycling process with a capacity retention of 94.2% at 0.5C and 87.6% at 1C after 1000 cycles with LiFePO 4 cathodes, providing new insights for the practical development of quasi-solid-state lithium metal battery.
研究领域:
电化学
·
材料科学
·
能源存储
·
界面化学
·
高分子化学
✓ 已验证
DOI
高影响因子
Nano Energy
·
2020
·
IF 16.602
Long Li,Chun Fang,Wenfei Wei,Lei Zhang,Zhao Ye,Gang He,Yunhui Huang
The huge volume change of silicon anode during cycling results in unstable solid electrolyte interface (SEI), causing rapid performance degradation . Natural SEI layer has a heterogeneous structure, results in the inhomogeneous Li + diffusion. The repeated destruction and regeneration of SEI aggravate the inhomogeneity of Li + diffusion at the interface, leading to non-uniform alloy reaction in the Si bulk. In this work, the silicon surface is passivated by an ultrathin uniform chitosan layer with abundant lithiophilic groups. The capacity of chitosan-coated Si (Si@CS) could reach 1500 mAh g −1 at a current density of 1 A g −1 , and the capacity retention remains 91% after 400 cycles. It is demonstrated that the oxygen and nitrogen atoms in chitosan are coordinated with Li + , providing uniformly distributed Li + transfer sites, results in a homogeneous Li + flux in the surface layer. Interestingly, a nano-scale ordered atomic arrangement is observed in the delithiated Si@CS, which contributes to more stable and reversible lithiation/delithiation reaction of the Si@CS electrode. It is proposed that optimizing the reaction interface on the Si surface is able to alter the Li-ion diffusion kinetics and structure transition behavior of silicon, which can improve the structure reversibility and stability during cycling.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
表面工程
·
锂离子电池
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Jianling Huang,ChengWei Liao,Hui Wang,YuJun Zhao,Liuzhang Ouyang,Jiangwen Liu,Min Zhu
Mg-based alloy anodes suffer from severe corrosion in conventional electrolytes (KOH solution) and this substantially obstructs the cycle life, which is a great challenge for using them in the Ni-MH battery. Herein, a high concentration tetramethylammonium hydroxide (TMAH) aqueous electrolyte with a special hydrate structure is explored and enables excellent cycle stability and high capacity for Mg-based alloy anodes. In this electrolyte, the Mg 0.4 Ti 0.1 Ni 0.5 alloy anode delivers a maximum discharge capacity of 466 mAh g −1 , and maintains 210 mAh g −1 after 100 cycles owing to the reduced corrosion rate , which are much better than that in 6 M KOH electrolyte, being 425 mAh g −1 and 69 mAh g −1 , respectively. Furthermore, by in-situ forming Cu coating on the Mg 0.4 Ti 0.1 Ni 0.5 electrode surface during charging process with the adding 0.01 M of Cu(OH) 2 in TMAH electrolyte, the corrosion of the electrode is further suppressed and the reversible capacity can reach 313 mAh g −1 after 100 cycles. The high conducting Cu coating can also increase the rate capability of the electrode by promoting the charge transfer. Thus, using TMAH electrolytes provides a new approach to promote the electrochemical performances of Ni-MH batteries with Mg-based alloy anodes.
研究领域:
材料科学
·
电化学
·
能源存储
·
金属腐蚀与防护
·
功能材料
·
电池技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 6
·2979-2984
·
IF 11.9
Wu Wei,Zhihong Wang,Liyun Yao,Hao Jiang,Chunzhong Li
Development of Ni-rich and Co-poor cathodes (Ni ≥ 80%, Co ≤ 5%) is indispensable for the next-generation lithium-ion batteries (LIBs) owing to the serious impact of scarce resources and fragile supply chain of cobalt, but they suffer from a more prominent lattice oxygen emission with serious Li/Ni intermixing as well as worsening crystal and interface structure. Herein, CeO2−x-coated LiNi0.9Co0.045Mn0.045Al0.01O2 has been demonstrated to stabilize lattice oxygen by the well-dispersed Al–O bonds and the reversible oxygen-storage protective layer. The in situ DEMS and ex situ spectral analyses verified the negligible O2 and CO2 emission, even charging to 4.4 V, and the formation of stable cathode–electrolyte interfacial membrane. The as-obtained cathode exhibited a reversible specific capacity as high as 223 mA h g−1 at 0.1C and 140 mA h g−1 even at 10C with 96.7% capacity retention at 1C after 100 cycles in a coin-type half-cell. About 90.1% capacity retention could still be obtained at 1C in a pouch-type full-cell after 300 cycles. This work provides a viable cathode for durable LIBs by stabilizing the lattice oxygen of Ni-rich and Co-poor cathodes.
研究领域:
电化学
·
材料科学
·
能源存储
·
锂离子电池
·
固态化学
·
表面科学
·
电极材料
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
Tianyao Ding,Dong Zheng,Huainan Qu,Weixiao Ji,Xiaoxiao Zhang,Dongping Lu,Gongwei Wang,Deyang Qu
An in-situ electrochemical optical diagnosis is the key to the investigation of electrode interface during a redox reaction . Because the morphology changes particularly, dendrite formation, dendrite shapes, solid electrolyte interface formation and gas generation can be revealed visually. The challenge of ensuring uniform current density on a flat Li anode in a liquid electrolyte is addressed and uniform Li plating is demonstrated. The dendrite shape change under different reduction current density is discussed. The Li dendrite shape change and the performance of Li anodes with a surface lamination of graphite and red phosphate are used as examples to demonstrate the capability of the in-situ optical cell. An in-situ electrochemical optical cell used in the investigation of the increasingly popular solid-state Li batteries has its own challenges. Due to the untransparent nature of a solid-state electrolyte, an optical investigation on a solid-state electrolyte Li battery needs to be done by exposing the cross-section of the cell. In addition, it is very difficult to assemble an optical cell with a brittle and fragile solid-state electrolyte in a glove box. A set of formation and transfer dies, and an optical cell are introduced. The Li dendrite growth at the interface can be observed in a solid-state Li cell.
研究领域:
电化学
·
材料科学
·
能源存储
·
固态电池
·
界面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）