A polymeric composite protective layer for stable Li metal anodes

Guo Suogang,Wang Li,Jin Yuhong,Piao Nan,Chen Zonghai,Tian Guangyu,Li Jiangang,Zhao Chenchen,He Xiangming 나노기술연구협의회 2020 Nano Convergence Vol.7 No.21

Lithium (Li) metal is a promising anode for high-performance secondary lithium batteries with high energy density due to its highest theoretical specific capacity and lowest electrochemical potential among anode materials. However, the dendritic growth and detrimental reactions with electrolyte during Li plating raise safety concerns and lead to premature failure. Herein, we report that a homogeneous nanocomposite protective layer, prepared by uniformly dispersing ­AlPO 4 nanoparticles into the vinylidene fluoride-co-hexafluoropropylene matrix, can effectively prevent dendrite growth and lead to superior cycling performance due to synergistic influence of homogeneous Li plating and electronic insulation of polymeric layer. The results reveal that the protected Li anode is able to sustain repeated Li plating/stripping for > 750 cycles under a high current density of 3 mA cm −2 and a renders a practical specific capacity of 2 mAh cm −2 . Moreover, full-cell Li-ion battery is constructed by using ­LiFePO 4 and protected Li as a cathode and anode, respectively, rendering a stable capacity after 400 charge/discharge cycles. The current work presents a promising approach to stabilize Li metal anodes for next-generation Li secondary batteries.

In-situ PECVD-enabled graphene-V₂O₃ hybrid host for lithium–sulfur batteries

Song, Yingze,Zhao, Wen,Wei, Nan,Zhang, Li,Ding, Feng,Liu, Zhongfan,Sun, Jingyu Elsevier 2018 Nano energy Vol.53 No.-

<P><B>Abstract</B></P> <P>Lithium–sulfur (Li–S) batteries have been regarded as promising candidates for current energy-storage technologies due to their remarkable advantages in energy density and theoretical capacity. However, one of the daunting challenges remained for advanced Li–S systems thus far deals with the synchronous suppression of polysulfide (LiPS) shuttle and acceleration of redox kinetics. Herein, a cooperative interface bridging adsorptive V<SUB>2</SUB>O<SUB>3</SUB> and conductive graphene is constructed <I>in-situ</I> by virtue of direct plasma-enhanced chemical vapor deposition (PECVD), resulting in the design of a novel V<SUB>2</SUB>O<SUB>3</SUB>-graphene hybrid host to synergize the LiPS entrapment and conversion. The redox kinetics and electrochemical performances of thus-derived cathodes were accordingly enhanced owing to the smooth adsorption-diffusion-conversion of LiPSs even at a sulfur mass loading of 3.7 mg cm<SUP>–2</SUP>. Such interfacial engineering offers us a valuable opportunity to gain insight into the comprehensive regulation of LiPS anchoring ability, electrical conductivity and ion diffusive capability in hybrid hosts on suppressing the LiPS shuttle and propelling the redox kinetics. Our devised PECVD route might pave a new route toward the facial and economic design of hetero-phased multi-functional hosts for high-performance Li–S systems.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Graphene-V<SUB>2</SUB>O<SUB>3</SUB> hybrid host was designed <I>in-situ</I> based on PECVD route. </LI> <LI> Thus-derived cathode showed a low capacity decay of merely 0.046% per cycle at 2 C after 1000 cycles. </LI> <LI> Cathodes with a relatively high sulfur mass loading (3.7 mg cm<SUP>–2</SUP>) were fabricated. </LI> <LI> The smooth adsorption-diffusion-conversion of polysulfides was thoroughly probed <I>via</I> experimental studies and DFT simulations. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The effect of S-functionalized and vacancies on V2C MXenes as anode materials for Na-ion and Li-ion batteries

Ya-Meng Li,Yong-Liang Guo,Zhao-Yong Jiao 한국물리학회 2020 Current Applied Physics Vol.20 No.2

The electrochemical properties of V2C and V2CT2 (T = O, S) MXenes with and without vacancy as anode materials for Na-ion and Li-ion batteries, have been studied using first-principles calculation. The present results indicate that the adsorption strength of Li-ion and Na-ion on V2CS2 are less than that of O-functionalized, together with a lower diffusion barrier. Simultaneously, V2CS2 monolayer exhibits lower open-circuit voltage (OCV) values of 0.72 and 0.49 V for Li- and Na-ion, respectively. Interestingly, the presence of atomic vanadium vacancy on V2CS2 monolayer exerts more prominent effects on enhancing adsorption strength than that of carbon vacancy for Li-ion and Na-ion, but with an exception for the diffusion of Li-ion and Na-ion on V2CS2 monolayer. The finding suggests that the V2CS2 monolayer is expected to be a potential candidate as anode material for Li-ion and Na-ion battery due to its lower open-circuit voltages and diffusion barriers.

Aqueous Processing and Effects of V2O5 on Microwave Dielectric Properties of Multilayer Li1.075Nb0.625Ti0.45O3 Ceramics

Shaochun Li,Yongjuan Geng,Tiejun Zhao,Zuquan Jin,Peng Zhang 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.1

In the present work, we report the development of an aqueous tape casting method and a low temperature co-firing process for fabrication of multilayer Li1.075Nb0.625Ti0.45O3 microwave dielectric ceramics. A co-binder, consisting of polyvinyl acetate latex (PVAc) and polyvinyl alcohol (PVA), was used to prepare aqueous Li1.075Nb0.625Ti0.45O3 tapes. PVA addition increased the tape flexibility and adhesiveness but resulted in decreased tensile strength. Rheological tests indicated that the aqueous ceramic slurry exhibited a typical shear thinning behavior without thixotropy, suitable for tape casting. Scanning electron microscopy (SEM) studies revealed that the green tapes have a defect-free surface and that the multilayer ceramics sintered at 900°C have a fine plate like, grainy microstructure of uniform size. At lower temperatures, increased densification rates were achieved by addition of V2O5 to Li1.075Nb0.625Ti0.45O3 ceramics. The saturated bulk densities and dielectric constants (εr) of Li1.075Nb0.625Ti0.45O3 multilayer ceramics affected by lower sintering temperatures with an increase in V2O5 doping, and then an improvement in the quality factor (Q × f value) of the samples was achieved at the lower sintering temperatures. As a result, the εr of 64.9 and the Q × f value of 8800 GHz were obtained in the sample with an addition of 3 wt. % V2O5, sintered at a temperature of 900°C. No reaction was observed between the ceramic and silver layers when sliver inner-electrode, was sintered with ceramic tapes at 900°C.

In-pile tritium release behavior and the post-irradiation experiments of Li4SiO4 fabricated by melting process

Zhao Linjie,Yang Mao,Xiao Chengjian,Gong Yu,Ran Guangming,Chen Xiaojun,Li Jiamao,Yue Lei,Chen Chao,Hou Jingwei,Wang Heyi,Long Xinggui,Peng Shuming 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1

Understanding the tritium release and retention behavior of candidate tritium breeder materials is crucial for breeder blanket design. Recently, a melt spraying process was developed to prepare Li4SiO4 pebbles, which were subsequently subjected to the in-pile tritium production and extraction platform in China Mianyang Research Reactor (CMRR) to investigate their in-situ tritium release behavior and irradiation performance. The results demonstrate that HT is the main tritium release form, and adding hydrogen to the purge gas reduces tritium retention while increasing the HT percent in the purge gas. Post-irradiation experiments reveal that the irradiated pebbles darken in color and their grains swell, but the mechanical properties remain largely unchanged. It is concluded that the tritium residence time of Li4SiO4 made by melt spraying method at 467 ◦C is approximately 23.34 h. High-density Li4SiO4 pebbles exhibit tritium release at relatively low temperatures (<600 ◦C) that is mainly controlled by bulk diffusion. The diffusion coefficient at 525 ◦C and 550 ◦C is 1.19 × 10 11 cm2/s and 5.34 × 10 11 cm2/s, respectively, with corresponding tritium residence times of 21.3 hours and 4.7 hours.

Preparation and Dieletrical Properties of Li1.075Nb0.625Ti0.45O3 Powders by Hydrothermal Method

Shaochun Li,Yongjuan Geng,Tiejun Zhao,Peng Zhang 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.4

A hydrothermal method has been developed and shown to be effective for the preparation of Li1.075Nb0.625Ti0.45O3(LNT) nano-particles. Hydrothermal reaction temperature was in the range from 120°C - 200°C. The crystalline structure and morphology of the prepared particles have been characterized by x-ray diffraction and scanning electron microscopy. Results indicate that hydrothermal temperature had a great effect on the phase formation and morphology of the particles. The prepared powders crystallized at 140°C, and the pure LNT phase was formed at 180°C. The size of LNT particles increased with increasing reaction temperature, and plate-like LNT particles with thickness of 15 - 30 mm and a diameter of 80 - 200 mm were obtained at 200°C. It was found that LNT powders synthesized at 180°C gave the LNT ceramics the highest microwave dielectric properties (εr = 66, Q×f = 8946 GHz) due to good crystallization and low particle size.

Promising Carbon Matrix Derived from Willow Catkins for the Synthesis of SnO2/C Composites with Enhanced Electrical Performance for Li-Ion Batteries

Yong Li,Yun Zhao,Canliang Ma,Yongxiang Zhao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.08

Willow catkins as a kind of seasonal biomass are harmful to human health in terms of causing respiratory ailments and skin anaphylaxis every spring. To explore the high-value utilization of willow catkins, in this study, we attempt to develop a kind of tin-based anode materials with willow catkin derived carbon (WCC) as the matrix. A designed solvent-thermal method involving thiourea as stabilizer and acetone–H2O mixture as solvent has been employed to fabricate SnO2–WCC composites, which exhibit uniform deposition of well-dispersed SnO2 nanoparticles on the surface of WCC. As an anode material for lithium-ion batteries (LIBs), the SnO2–WCC composite delivered a stable discharge capacity of 565mAh g -1 at 100mA g -1 after 70 cycles and a good rate capability of 349mAh g -1 at 1000mA g -1. The high dispersity of SnO2 nanoparticles and high conductivity of WCC are both believed to contribute to the excellent electrochemical performances. These results suggest the potential of willow catkins derived carbonaceous materials applied in anode materials of LIBs and shed light on the creation of advanced carbon materials from other biomass materials towards energy storage applications.

Synchronous immobilization and conversion of polysulfides on a VO₂-VN binary host targeting high sulfur load Li-S batteries

Song, Yingze,Zhao, Wen,Kong, Long,Zhang, Li,Zhu, Xingyu,Shao, Yuanlong,Ding, Feng,Zhang, Qiang,Sun, Jingyu,Liu, Zhongfan The Royal Society of Chemistry 2018 ENERGY AND ENVIRONMENTAL SCIENCE Vol.11 No.9

<P>Lithium-sulfur (Li-S) batteries are deemed as one of the most promising next-generation energy storage systems. However, their practical application is hindered by existing drawbacks such as poor cycling life and low Coulombic efficiency due to the shuttle effect of lithium polysulfides (LiPSs). We herein present an <I>in situ</I> constructed VO2-VN binary host which combines the merits of ultrafast anchoring (VO2) with electronic conducting (VN) to accomplish smooth immobilization-diffusion-conversion of LiPSs. Such synchronous advantages have effectively alleviated the polysulfide shuttling, promoted the redox kinetics, and hence improved the electrochemical performance of Li-S batteries. As a result, the sulfur cathode based on the VO2-VN/graphene host exhibited an impressive rate capability with ∼1105 and 935 mA h g<SUP>−1</SUP> at 1C and 2C, respectively, and maintained long-term cyclability with a low capacity decay of 0.06% per cycle within 800 cycles at 2C. More remarkably, favorable cyclic stability can be attained with a high sulfur loading (13.2 mg cm<SUP>−2</SUP>). Even at an elevated temperature (50 °C), the cathodes still delivered superior rate capacity. Our work emphasizes the importance of immobilization-diffusion-conversion of LiPSs toward the rational design of high-load and long-life Li-S batteries.</P>

Vanadium Dioxide-Graphene Composite with Ultrafast Anchoring Behavior of Polysulfides for Lithium-Sulfur Batteries

Song, Yingze,Zhao, Wen,Zhu, Xingyu,Zhang, Li,Li, Qiucheng,Ding, Feng,Liu, Zhongfan,Sun, Jingyu American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.18

<P>The lithium-sulfur (Li-S) battery has been deemed as one of the most promising energy-storage systems owing to its high energy density, low cost, and environmental benignancy. However, the capacity decay and kinetic sluggishness stemming from polysulfide shuttle effects have by far posed a great challenge to practical performance. We herein demonstrate the employment of low-cost, wet-chemistry-derived VO<SUB>2</SUB> nanobelts as the effective host additives for the graphene-based sulfur cathode. The VO<SUB>2</SUB> nanobelts displayed an ultrafast anchoring behavior of polysulfides, managing to completely decolor the polysulfide solution in 50 s. Such a fast and strong anchoring ability of VO<SUB>2</SUB> was further investigated and verified by experimental and theoretical investigations. Benefitting from the synergistic effect exerted by VO<SUB>2</SUB> in terms of chemical confinement and catalytic conversion of polysulfides, the Li-S batteries incorporating VO<SUB>2</SUB> and graphene manifested excellent cycling and rate performances. Notably, the batteries delivered an initial discharge capacity of 1405 mAh g<SUP>-1</SUP> when cycling at 0.2 C, showed an advanced rate performance of ∼830 mAh g<SUP>-1</SUP> at 2 C, and maintained a stable cycling performance at high current densities of 1, 2, and 5 C over 200 cycles, paving a practical route toward cost-effective and environmentally benign cathode design for high-energy Li-S batteries.</P> [FIG OMISSION]</BR>

Antimony Selenide Nanorods Decorated on Reduced Graphene Oxide with Excellent Electrochemical Properties for Li-Ion Batteries

Wang, Xia,Wang, Hong,Li, Qiang,Li, Hongsen,Xu, Jie,Zhao, Guoxia,Li, Hongliang,Guo, Peizhi,Li, Shandong,Sun, Yang-kook The Electrochemical Society 2017 Journal of the Electrochemical Society Vol.164 No.13

<P>A promising anode material for lithium-ion batteries (LIBs) consisting of Sb2Se3 nanorods and reduced graphene oxide (rGO) sheets has been prepared by an effective solvothermal approach. The synergetic effect between Sb2Se3 nanorods and rGO matrix provides not only high conductivity paths and strong electron contact interface, but also alleviates the volume change of Sb2Se3 nanorods, resulting in excellent lithium-storage performance. When tested as an anode material for LIBs, a high capacity of 868.30 mAh g(-1) can be retained after 100 cycles at 200 mA g(-1). Even at 2000 mA g(-1), a satisfactory capacity of 430.40 mAh g(-1) after long 550 cycles can be delivered. Ex situ X-ray diffraction study suggests that the Sb2Se3/rGO composite follows the combined Li+ intercalation, conversion reaction and alloying reaction mechanism. These features suggest the Sb2Se3/rGO composite a viable choice for application as an anode material in high-performance LIBs. (C) 2017 The Electrochemical Society. All rights reserved.</P>