查找使用阿拉丁产品的科研文献

Preparation and SO2 capture performance of NCP10/LiOH carbon-based composite for deep desulfurization

Li Xing,Huhe Taoli,Zeng Tao,Ling Xiang,Huang Hongyu,Chen Yong

Carbon materials mainly capture sulfur dioxide (SO 2 ) from gas through physical adsorption, therefore their SO 2 capture performance will decrease with the increase in desulfurization temperature. In order to meet the stringent requirements of deep desulfurization, further improvements on carbon materials are necessary, improving their SO 2 capture performance and adaptability to changes in desulfurization temperature. In this study, a carbon material (NCP10) was modified with various alkali metal compounds with the aim of enhancing the SO 2 capture performance and adaptability to temperature changes. The results showed that the NCP10/LiOH composite had the best average SO 2 removal rate (100%) and SO 2 capture capacity ( \({113}.{6} \;{\text{mg}}_{{{\text{SO}}_{2} }} /{\text{g}}_{{{\text{material}}}}\) ) within the first hour of reacting at 60 °C, the SO 2 removal rate and SO 2 capture capacity of the NCP10/LiOH composite were 29% and 29% higher than those of the pure NCP10 material, respectively. While the SO 2 capture performance of the NCP10 modified with LiCl, Li 2 CO 3 , NaOH and KOH were not sufficient for deep desulfurization, the SO 2 capture performance of the NCP10/LiOH(2:1) composite was able to meet the requirements of deep desulfurization in the temperature range of 25–100 °C by the physical adsorption and chemical absorption synergistically effect.

Quasi-In Situ XPS Insights into the Surface Chemistry of Garnet-Type Li6.4La3Zr1.4Ta0.6O12 Solid-State Electrolytes: The Overlooked Impact of Pretreatments and a Direct Observation of the Formation of LiOH

Yifan Zhou,Aosong Gao,Mingqiu Duan,Xiaoqi Zhang,Muzi Yang,Li Gong,Jian Chen,Shuqin Song,Fangyan Xie,Hao Jia,Yi Wang

Garnet-type Li6.4La3Zr1.4Ta0.6O12 (LLZTO) is a highly promising solid-state lithium metal battery electrolyte due to its exceptional ionic conductivity and electrochemical stability. However, when exposed to air, a passivation layer can be spontaneously formed on the garnet-type electrolyte, deteriorating its wettability with metallic lithium (Li) and impeding the lithium ion transfer at the Li–garnet electrolyte interface. The passivation layer is considered a critical issue for garnet-type solid electrolytes. Despite intensive research, the formation mechanism of the passivation film remains poorly understood. The key to elucidating the formation mechanism is to obtain a pristine garnet electrolyte surface and study how the pristine garnet electrolyte interacts with air. In this study, different passivation layer removal pretreatments were performed to expose pristine garnet electrolytes, and their impacts on the samples were systematically studied. The results reveal the overlooked negative impacts of vacuum annealing and acid treatment on LLZTO, which are indicated by the severe loss of Li and O and the formation of additional Li-depleted metal oxides. It was confirmed that argon annealing is the only viable approach to remove the passivation layer without introducing concomitant contaminations to LLZTO. Based on this method, we directly evidenced the formation of LiOH on LLZTO under rarefied air using quasi-in situ X-ray photoelectron spectroscopy. It was confirmed that the loss of Li and O ions, rather than Li+/H+ exchange, drives the formation of LiOH in the passivation layer. These results not only provide a better understanding of the surface and interface chemistry of LLZTO but also reveal a reliable surface treatment for the LLZTO sample.

Zn–Al LDH nanosheets exfoliated in a LiOH/urea solution in situ: an effective strategy for fabricating cellulosic fibres with enhanced mechanical properties

Zhang Shanbei,Chen Zanmei,He Hongwei,Jiang Yijun

The alkali/urea system is an economical and environmentally friendly solvent system for dissolving cellulose. However, the mechanical performance of cellulose derived materials (such as fibres or films) treated with alkali/urea must be improved. The capacity of this system for cellulose dissolution is limited and the mechanical properties of the regenerated cellulose fibres are still unsatisfactory. Here, cotton linter pretreated with peracetic acid (PAA) was dissolved in a LiOH/urea aqueous suspension in which Zn–Al layered double hydroxide (Zn–Al LDH) nanosheets (NS thickness = 3 nm) were exfoliated in situ. After wet spinning, the strength and toughness of the regenerated cellulose fibres reached 290 ± 7.66 MPa and 23.5 ± 4.40 MJ/m 3 respectively, which were 66.7% and 150% higher than those without the LDH NS treatment. It is interesting to note that the synergistic effect of Zn 2+ and Al 3+ distributed on the surface of the LDH host layer significantly improved the solubility of cellulose at low temperature and the interaction between the cellulose and LDH NSs also improved the mechanical performance. This work provides a strategy for improving both the solubility of cellulose in the alkali/urea system and the mechanical properties of regenerated cellulose fibres. Graphical abstract

Water-Trapping Single-Atom Co-N4/Graphene Triggering Direct 4e− LiOH Chemistry for Rechargeable Aprotic Li–O2 Batteries

Wenjing Zhang,Jian Zheng,Ruoyu Wang,Li Huang,Junkai Wang,Tianran Zhang,Xiangfeng Liu

Lithium–oxygen (Li–O 2 ) batteries have received extensive attention owing to ultrahigh theoretical energy density. Compared to typical discharge product Li 2 O 2 , LiOH has attracted much attention for its better chemical and electrochemical stability. Large-scale applications of Li–O 2 batteries with LiOH chemistry are hampered by the serious internal shuttling of the water additives with the desired 4e − electrochemical reactions. Here, a metal organic framework-derived “water-trapping” single-atom-Co-N 4 /graphene catalyst (Co-SA-rGO) is provided that successfully mitigates the water shuttling and enables the direct 4e − catalytic reaction of LiOH in the aprotic Li–O 2 battery. The Co-N 4 center is more active toward proton-coupled electron transfer, benefiting - direction 4e − formation of LiOH. 3D interlinked networks also provide large surface area and mesoporous structures to trap ≈12 wt% H 2 O molecules and offer rapid tunnels for O 2 diffusion and Li + transportation. With these unique features, the Co-SA-rGO based Li–O 2 battery delivers a high discharge platform of 2.83 V and a large discharge capacity of 12 760.8 mAh g −1 . Also, the battery can withstand corrosion in the air and maintain a stable discharge platform for 220 cycles. This work points out the direction of enhanced electron/proton transfer for the single-atom catalyst design in Li–O 2 batteries.

MgAl Saponite as a Transition-Metal-Free Anode Material for Lithium-Ion Batteries

Jian Zhang,Tianlin Li,Qingyan Yuan,Yunjia Wu,Yibo Dou,Jingbin Han

Transition-metal compounds (oxides, sulfides, hydroxides, etc.) as lithium-ion battery (LIB) anodes usually show extraordinary capacity larger than the theoretical value due to the transformation of LiOH into Li2O/LiH. However, there has rarely been a report relaying the transformation of LiOH into Li2O/LiH as the main reaction for LIBs, due to the strong alkalinity of LiOH leading to battery deterioration. In this work, layered silicate MgAl saponite (MA-SAP) is applied as a −OH donor to generate LiOH as the anode material of LIBs for the first time. The MA-SAP maintains a layered structure during the (dis)charging process and has zero-strain characteristic on the (001) crystal plane. In the discharging process, Mg, Al, and Si in the saponite sheets become electron-rich, while the active hydroxyl groups escape from the sheets and combine with lithium ions to form LiOH in the “caves” on sheets, and the LiOH continues to decompose into Li2O and LiH. Consequently, the MA-SAP delivers a maximum capacity of 536 mA h·g–1 at 200 mA·g–1 with a good high-current discharging ability of 155 mA h·g–1 after 1000 cycles under 1 A·g–1. Considering its extremely low cost and completely nontoxic characteristics, MA-SAP has great application prospects in energy storage. In addition, this work has an enlightening effect on the development of new anodes based on extraordinary mechanisms.

Lithium Extraction from Molten LiOH by Using a Liquid Tin Cathode

Tang Zujian,Guan Xiaofei

Abstract Lithium is a critical metal with a wide range of applications in energy, electronics, and chemical industry. Currently, the industrial method for Li metal extraction relies on electrolysis of molten LiCl and suffers from various safety, cost, and environmental issues. In this work, we report electrochemical extraction of Li from molten LiOH by using a liquid tin (Sn) cathode. The use of liquid Sn cathode offers various advantages, such as lowering the dissociation potential of LiOH and easy collection of the metallic Li. Electrochemical and materials characterization results reveal that a plunge of electrolysis current occurs in the electrolyser without using a porous alumina membrane, due to the formation of a Li 2 O passivation layer at the cathode/electrolyte interface. In the electrolyser with a porous alumina membrane, continuous electrolysis has been achieved, and the side surface of the liquid Sn is identified to be the effective interface for Li electrodeposition. In addition, we demonstrate the use of the Li–Sn product for the synthesis of acetylene (C 2 H 2 ), a widely used fuel and chemical feedstock. Graphical Abstract

Formation and Effect of Residual Lithium Compounds on Li-Rich Cathode Material Li1.35[Ni0.35Mn0.65]O2

Chun-xian Zhou,Peng-bo Wang,Bao Zhang,Lin-bo Tang,Hui Tong,Zhen-jiang He,Jun-chao Zheng

Li-rich cathode materials are regarded as ideal cathode materials, owing to their excellent electrochemical capacity. However, residual lithium compounds, which are formed on the surface of the materials by reacting with moisture and carbon dioxide in ambient atmosphere, can impair the surface structure, injure the capacity, and impede the electrode fabrication using Li-rich materials. Exposure to air atmosphere causes the formation of residual lithium compounds; the formation of such compounds is believed to be related to humidity, temperature, and time during handling and storage. In this study, we demonstrated for the first time an artificial strategy for controlling time, temperature, and humidity to accelerate exposure. The formation and effect of residual lithium compounds on Li-rich cathode material Li1.35[Ni0.35Mn0.65]O2 were systematically investigated. The residual lithium compounds formed possessed primarily an amorphous structure and were partially coated on the surface. These compounds include LiOH, Li2O, and Li2CO3. Li2CO3 is the major component in residual lithium compounds. The presence of residual lithium compounds on the material surface led to a high discharge capacity loss and large discharge voltage fading. Understanding the formation and suppressing the effect of residual lithium compounds will help prevent their unfavorable effects and improve the electrochemical performance.

Preparation of high-performance cellulose composite membranes from LiOH/urea solvent system

Yinke Liu,Shuman Xu,Mengfan Jing,Yuan Wei,Hua Deng,Qiang Fu

Bipolar membrane electrodialysis with isolation chamber enables high-purity LiOH production with ordinary membranes

Duyi He,Weicheng Fu,Zihao Wang,Junying Yan,Huangying Wang,Ruirui Li,Baoying Wang,Xiaochun Chen,Yaoming Wang,Tongwen Xu

Currently, bipolar membrane electrodialysis (BMED) is recognized as an eco-friendly technique to recycle lithium from waste lithium-ion batteries. However, the application of ordinary bipolar membranes has the disadvantage of unsatisfactory product purity due to undesired ion leakage. Herein, we proposed isolation chamber bipolar membrane electrodialysis (ICBMED) to inhibit coion migration, thereby increasing the purity of the regenerated acid and alkali. The experimental results indicate that 97.7%–99.3% of the LiOH generated by the ICBMED using domestic membranes was generated, which is much greater than the 85.7%–94.4% obtained without an isolation chamber. The total cost of the ICBMED for LiOH production with inexpensive domestic membranes was 1.65$/kg-LiOH (US) at 400 A/m 2 , which is lower than the cost of 1.91$/kg-LiOH (US) for flagship membranes with identical product quality. BMED with an isolation chamber provides a viable solution for acid–base production by balancing product quality and cost.

Novel membranes prepared from collagen fibrils using LiOH/urea aqueous system crosslinked by tannic acid

Changkun Ding,Yu Zhang,Xu Zeng,Ruimin Wang,Jing Li

In this work, a rapid and controlled exfoliation of collagen fibrils from bovine tendons in LiOH/urea aqueous system combined with freeze-thaw cycles was developed to preserve the native structure of collagen. The prepared collagen fibril membranes by vacuum filtration approach exhibited excellent transparency and mechanical properties. Particularly, the optimal tensile strength can reach 144.2 and 1.51 MPa in the dry and wet states, respectively, which is significantly superior to traditional acid-soluble collagen membrane. The fibril membranes also showed good resistance in acids, alkalis and organic solvents, as well as thermal stability. Moreover, the use of tannic acid as a bio-crosslinking agent further improved their mechanical performances. This work provides a new avenue for the preparation of collagen-based materials with native mesostructures.

pH-Sensitive Vesicles and Rheological Properties of PFLA/NaOH/H2O and PFLA/LiOH/H2O Systems

Panfeng Long,Aixin Song,Dong Wang,Renhao Dong,Jingcheng Hao

The formation of pH-sensitive vesicles and the rheological properties of the mixtures of perfluorolauric acid (PFLA) and its salts (PFL-Na and PFL-Li) neutralized via NaOH or LiOH were investigated in aqueous solution. When the right mixing ratios of the ionized to nonionzed PFLA molecules with a very high Krafft point are established, vesicles can spontaneously form at room temperature. The vesicles spontaneously formed in the PFLA/PFL-Na/H2O system with the rigid fluorocarbon chains were determined by atomic force microscopy images. Compared to those of hydrocarbon amphiphiles, these vesicle samples, which can be kept for 2 years at room temperature, are more stable. The phase transition from the vesicle phase to the lamellar lyotropic liquid crystal phase with the increase of pH was determined by freeze-fracture transmission electron microscopy images in the PFLA/PFL-Li/H2O system. The system of perfluoro fatty acid vesicles exhibits much more interesting rheological properties, compared to hydrocarbon fatty acid vesicles. The perfluoro fatty acid vesicle solutions display a much higher yield stress and viscoelastic properties, which depend on two factors: (i) the fluorinated alkyl chains of PFL–, which are in the crystalline state at room temperature because of their rigid chains compared to analogous hydrocarbon chains, and (ii) the packing of the vesicles, which is very dense. This is the first time that pH-sensitive vesicles exhibiting birefringence were constructed through ionizing perfluoro fatty acid, which may direct primarily toward acquiring an understanding of the mechanism of vesicles depending on the right mixing ratios of the ionized to the nonionzed perfluoro fatty acid molecules with a very high Krafft point and secondarily to expand the development of fluorinated surfactants in both fundamental research and practical applications.

High-rate Li4Ti5O12/porous activated graphene nanoplatelets composites using LiOH both as lithium source and activating agent

Dongdong Wang,Zhongqiang Shan,Xiaoyan Liu,Ren Na,Juan Wang,Huitian Liu,Jianhua Tian

The Li 4 Ti 5 O 12 /activated graphene nanoplatelets (Li 4 Ti 5 O 12 /a-GNPs) composites are prepared via a low-cost, green, one-pot hydrothermal process by using LiOH both as lithium source and activating agent for the first time. The LiOH solution concentration and hydrothermal time are optimized to obtain the pure Li 4 Ti 5 O 12 /a-GNPs. The synergistic effects of the nanosized Li 4 Ti 5 O 12 and the three-dimensional porous a-GNPs endow the composites with convenient lithium ion diffusion channels and efficiently conductive structures for electron and ion transport. As anticipated, the Li 4 Ti 5 O 12 /a-GNPs deliver an outstanding rate capability of 125 and 113 mA h g −1 at 80 and 100 C, respectively, and an excellent cycling stability with 90.21% capacity retention after 2000 cycles at 10 C. These results are much better than those of the Li 4 Ti 5 O 12 /GNPs and pure Li 4 Ti 5 O 12 , demonstrating Li 4 Ti 5 O 12 /a-GNPs are promising anode materials for lithium-ion batteries of high current density applications.