CHEMISTRY OF MATERIALS
·
2015
·
IF 8.354
Xinmiao Liang,Liying Wang,Yangming Jiang,Jian Wang,Huan Luo,Chaoyang Liu,Jiwen Feng
Li10GeP2S12 (LGPS) is a new solid electrolyte of the highest Li ionic conductivity reported as of now. An anisotropic 3D Li ionic transport network consisting of an ultrafast Li 1D diffusion tunnel and fast in-plane 2D pathways was previously predicted by molecular dynamics simulations. In this paper, we have studied in detail the Li ion dynamics in LGPS by multiple solid-state NMR methods. Two different Li motion processes, characterized by apparently different activation energies of 0.16 eV and 0.26 eV, were unambiguously probed by both 7Li and 31P solid-state NMR and assigned to Li ion diffusions in the 1D tunnel and in the 2D plane, respectively. 31P spin-locking relaxation measurement further reveals that interstitial position Li(4) is active for in-plane Li migration.
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DOI
高影响因子
Energy Advances
·
2023
·Vol. 2
·期 10
·1685-1692
·
IF 0
Guozhe Ma,Yu Zheng,Fanbo Meng,Renzong Hu
High-entropy oxides (HEOs) have started to attract widespread interest as anode materials for lithium-ion batteries (LIBs), because of their high theoretical discharge capacities, fast ionic conductivity, and stable structure caused by the unique entropy stabilization effect and the “cocktail” effect. However, the lithiation mechanism of HEO anode is still conversional, which prevents its further development. Herein, we propose an Li2O-doping strategy for improving the lithium storage ability of HEO anodes. Li2O is successfully introduced into the spinel high-entropy oxide to obtain a (FeMgNiCrMnLi)3O4 anode (Li-SHEO) via a solution combustion synthesis and ball milling method. Experimental results show Li doping would induce the growth of oxygen vacancies and regulate the conversion reactions during the discharge process, leading to improved electrochemical performance. As a result, the lithiation process of an Li-SHEO anode includes an enhanced Li+ ion intercalation process and a typical conversion reaction. Compared with the (FeMgNiCrMnLi)3O4 (SHEO) anode, the Li-SHEO anode shows a high reversible discharge capacity of 850.7 mA h g−1 after 200 cycles under a large current density of 2.0 A g−1.
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DOI
Nanomaterials
·
2021
·Vol. 11
·期 10
·2562
·
IF 5.076
Shuang Lian,Yu Wang,Haifeng Ji,Xiaojie Zhang,Jingjing Shi,Yi Feng,Xiongwei Qu
The development of solid-state polymer electrolytes is an effective way to overcome the notorious shuttle effect of polysulfides in traditional liquid lithium sulfur batteries. In this paper, cationic cyclopropenium based cross-linked polymer was firstly prepared with the one pot method, and then the counter ion was replaced by TFSI−anion using simple ion replacement. Cationic cyclopropenium hyper-crosslinked polymer (HP) was introduced into a polyethylene oxide (PEO) matrix with the solution casting method to prepare a composite polymer electrolyte membrane. By adding HP@TFSI to the PEO-based electrolyte, the mechanical and electrochemical properties of the solid-state lithium-sulfur batteries were significantly improved. The PEO-20%HP@TFSI electrolyte shows the highest Li+ionic conductivity at 60 °C (4.0 × 10−4S·cm−1) and the highest mechanical strength. In the PEO matrix, uniform distribution of HP@TFSI inhibits crystallization and weakens the interaction between each PEO chain. Compared with pure PEO/LiTFSI electrolyte, the PEO-20%HP@TFSI electrolyte shows lower interface resistance and higher interface stability with lithium anode. The lithium sulfur battery based on the PEO-20%HP@TFSI electrolyte shows excellent electrochemical performance, high Coulombic efficiency and high cycle stability. After 500 cycles, the capacity of the lithium-sulfur battery based on PEO-20%HP@TFSI electrolytes keeps approximately 410 mAh·g−1at 1 C, the Coulomb efficiency is close to 100%, and the cycle capacity decay rate is 0.082%.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 11
·4295-4303
·
IF 3.288
Chao Wang,Xing Li,Yuzhou Liu,Nan Gao,Xing Xin
In this work, BaLi2Ti6O14 nanofibers coated by a thin carbon layer were rationally designed and synthesized by a controlled electrospinning process and a simple annealing process. The carbon content of the composite is as low as 1.91 wt%. This thin carbon layer is considered to contribute to remarkably improving the rate capability. Furthermore, BaLi2Ti6O14@C nanofibers can deliver a high reversible capacity of 95.0 mA h g−1 with a capacity retention of 83.4% at a high current density of 1000 mA g−1 after 800 cycles. Analysis of the electrochemical results showed that the existence of the carbon coating layer plays a positive role in improving the structural stability and ionic transport of BaLi2Ti6O14 during the charge/discharge processes, thereby indicating a general method for improving the electrochemical performance of electrode materials with poor electrical conductivity.
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Xiao Bai,Hui Zhang,Junpin Lin
Although the utilization of conducting polymers in silicon anodes as both a conductive agent and binder is extremely attractive, key challenges exist in maintaining constant electric connectivity with silicon, especially during long-term cycling. In addition to the in-situ formation of polyaniline (PANI) encapsulating silicon nanoparticles (SiNPs) inside, herein PANI is also used as a three-dimensional (3D) bridge to interconnect the outside carbon nanotubes functionalized with carboxyl groups (CNFs-COOH) via electrostatic attraction and π-π conjugation. Further improvements in Li-ion diffusion kinetics and cycling properties can be achieved by low-temperature sintering the double-protected SiNPs without destruction of the 3D PANI conductive skeleton. Such a novel composite (i.e. Si@C/PANI-CNT) with a 3D hierarchically interconnected architecture containing 52 wt% SiNPs delivers a high discharge capacity of 879 mAh g −1 at 0.5 A g −1 with a capacity loss of 0.084% per cycle after 500 cycles. Increasing the current density to 1 A g −1 , no big change in the 500 th discharge capacity (817 mAh g −1 ) is found and the specific capacity still stabilizes around 605 mAh g −1 over 1000 cycles.
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DOI
高影响因子
Energy & Environmental Materials
·
2022
·Vol. 7
·期 1
·e12498
·
IF 13.443
Zhengyi Lu,Lin Peng,Yi Rong,Enli Wang,Ruhua Shi,Hongxun Yang,Yadong Xu,Ruizhi Yang,Chao Jin
Poly(ethylene oxide) (PEO) and Li 6.75 La 3 Zr 1.75 Ta 0.25 O 12 (LLZTO)-based composite polymer electrolytes (CPEs) are considered one of the most promising solid electrolyte systems. However, agglomeration of LLZTO within PEO and lack of Li + channels result in poor electrochemical properties. Herein, a functional supramolecular combination (CD-TFSI) consisting of active β-cyclodextrin (CD) supramolecular with self-assembled LiTFSI salt is selected as an interface modifier to coat LLZTO fillers. Benefiting from vast H-bonds formed between β-CD and PEO matrix and/or LLZTO, homogeneous dispersion and tight interface contact are obtained. Moreover, 6 Li NMR spectra confirm a new Li + transmission pathway from PEO matrix to LLZTO ceramic then to PEO matrix in the as-prepared PEO/LLZTO@CD-TFSI CPEs due to the typical cavity structure of β-CD. As a proof, the conductivity is increased from 5.3 × 10 −4 S cm −1 to 8.7 × 10 −4 S cm −1 at 60 °C, the Li + transference number is enhanced from 0.38 to 0.48, and the electrochemical stability window is extended to 5.1 V versus Li/Li + . Li‖LiFePO 4 CR2032 coin full cells and pouch cells prove the practical application of the as-prepared PEO/LLZTO@CD-TFSI CPEs. This work offers a new strategy of interface modifying LLZTO fillers with functional supramolecular combination to optimize PEO/LLZTO CPEs for solid lithium batteries.
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Jian-Ling Huang,Le-Qing Fan,Yun Gu,Cheng-Long Geng,Hui Luo,Yun-Fang Huang,Jian-Ming Lin,Ji-Huai Wu
To obtain high-performance lithium-ion capacitors (LICs), superior Fe 3 O 4 /reduced graphene oxide (rGO) composite has been synthesized by a facile one-step solvothermal method. The morphologies and structures of materials were characterized by powder X-ray diffraction, Raman spectroscopy , X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and N 2 adsorption–desorption isotherm. Electrochemical performances of materials were evaluated by cyclic voltammetry , galvanostatic charge/discharge and electrochemical impedance spectroscopy in half cell. Compared with the agglomerated pure Fe 3 O 4 , the high-crystallinity Fe 3 O 4 particles uniformly distributes onto the rGO sheets and the Fe 3 O 4 particles possess smaller size of 150–250 nm in Fe 3 O 4 /rGO composite. Therefore, the introduction of rGO can not only increase the specific surface area but also enhance the electrical conductivity of electrode material, leading to the improvement of electrochemical performances. The Fe 3 O 4 /rGO composite can reach high specific capacity of 1065 mAh g −1 at 0.1 A g −1 , and exhibits good rate capability and cyclic stability. Using the as-prepared Fe 3 O 4 /rGO composite as negative electrode and activated carbon (AC) as positive electrode, a Fe 3 O 4 /rGO//AC LIC was fabricated. The assembled Fe 3 O 4 /rGO//AC LIC presents outstanding energy density of 98.8 Wh kg −1 and power density of 3.4 kW kg −1 . Moreover, 78.9% of capacity can be retained after 1000 charge/discharge cycles.
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Saisai Zhang,Hailei Zhao,Jie Wang,Tao Xu,Kangkang Zhang,Zhihong Du
As promising next generation energy storage system, all solid state lithium batteries offer great potential for achieving high energy density and improved safety over lithium batteries with liquid counterpart. Dense microstructure with high ionic conductivity are prerequisites for solid electrolyte. The promising Li-garnet electrolyte suffers from poor sinterability, which results in porous structure and large grain boundary resistance. Herein, we report that the poor sinterability of garnet Li 7 La 3 Zr 2 O 12 is most likely related to the Li 2 CO 3 formed on particle surface, and SiO 2 is an efficient additive to scavenge the surface Li 2 CO 3 and so significantly improve the densification of electrolyte. The reaction product Li 4 SiO 4 of SiO 2 with Li 2 CO 3 is a Li-ion conductor, which exists at grain boundary and so can facilitate the grain boundary lithium ion diffusion. An addition of 1 mol.% SiO 2 , with respect to the total lithium content in Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO), significantly increases the relative density of LLZTO pellet by 28% and the conductivity by one order of magnitude, reaching 3.84 × 10 −4 S cm −1 at room temperature by a conventional solid state sintering. A symmetric lithium cell assembled with such dense LLZTO electrolyte can cycle well for 260 h compared with unmodified LLZTO running only for 72 h before short-circuit.
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DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Fei Chen,Yiluo Zhang,Qing Hu,Shiyu Cao,Shangbin Song,Xinqi Lu,Qiang Shen
Traditional liquid lithium-sulfur batteries have two key problems: poor safety and shuttle effect . These two challenges can be overcome by using solid-state electrolytes. But poor ionic and electronic conductivity due to solid/solid contact between the electrode and the electrolyte for all-solid-state lithium-sulfur batteries (ASSLSBs). Here, we have synthesized Li 6.4 Ga 0.2 La 3 Zr 2 O 12 (LLZO) conductive ceramics with high ionic conductivity . LLZO is used as the lithium-ion conductor and multi-walled carbon nanotubes (MWCNt) are used as the electronic conductor to form S/MWCNt/LLZO by the thermal diffusion method, resulting in an e − /S/Li + conductive network. The prepared S/MWCNt/LLZO composite material, composite solid electrolyte, and lithium metal are assembled into ASSLSBs. After 50 cycles, the high capacity of 825 mAh·g −1 is maintained with 72.62% capacity retention at 0.2C and 45 °C. The higher capacity indicates the success of forming a conductive network that can improve the electrochemical performance of ASSLSBs. At 0.2C, the capacity of the S/MWCNt/LLZO composite cathode remains at 873 mAh·g −1 after 60 cycles when the operating temperature is increased to 60 °C, indicating good cycle performance.
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DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Wenyan Li,Fangchao Liu,Zhongli Shen,Han Hu,Zhengwen Fu
Selenium sulfide (SeS 2 ) shows attractive advantages of high capacity for lithium storage. Here, a free-standing ultra-high dispersion Selenium sulfide three-dimensional graphene (SeS 2 -3DG) was synthesized and used as a cathode material in all-solid-state Lithium-Selenium sulfide (Li-SeS 2 ) batteries for enhancing rate performance and utilization of SeS 2 . SeS 2 -3DG achieved the utilization rate of 103% with capacity of 1,163 mAh g -1 and remained 538.56 mAh g -1 after 20 cycles under 1/2C. It should be noted that SeS 2 -3DG exhibited outstanding rate performance, which discharged under 7C with capacity as high as 990 mAh g -1 . Due to the high utilization rate of SeS 2 , charge and discharge products of Li-SeS 2 batteries were observed by high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). The mechanism of lithium sulfide (Li 2 S)/ Lithium selenide (Li 2 Se) ↔ SeS 2 was confirmed.
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DOI
高影响因子
Journal of the American Chemical Society
·
2023
·
IF 15
Shang Shi,Zhenzhen Shen,Shanshan Li,Qian Wang,Rui Wen,Bing Liu
The use of carbon materials in porous electrodes has impressive advantages. However, precisely tailoring the multilevel pore structure of carbon electrodes remains an unsolved challenge. Here, we report a highly efficient site-selective growth strategy to synthesize colloidal carbon rings by templating patchy droplets. Carbon rings are used for the direct fabrication of self-standing porous electrodes with hierarchical pores for lithium–oxygen batteries (LOBs). In situ atomic force microscopy reveals that during discharge the discharge products densely nucleate and grow on carbon rings, demonstrating that such rings are a very potential electrode material in LOBs. The hollow carbon ring electrode (HCRE) possesses micrometer-scale channels formed by random packing of rings and nanochannels consisting of ring-shaped hollow cavities connected by nanosized pores in the wall. Both channels contribute to ion transportation and gas diffusion, but the storage of the discharge products mainly lies in micrometer-scale channels, leading to a high discharge capacity of LOBs (20 658 mAh/g). Our work paves a new way to construct hierarchically porous electrodes for application in electrocatalysis and electrochemical energy storage.
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DOI
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 20
·6644-6650
·
IF 4.174
Zongtang Li,Xiao Lian,Mingzai Wu,Fangcai Zheng,Yuanhao Gao,Helin Niu
Manganese dioxide (MnO2) is a high-performance anodic material and applied widely in lithium-ion batteries (LIBs). However, some intrinsic limitations originate from the low ionic conductivity, high polarization, and severe volume expansion of this type of material. In this work, we generated a one-dimensional porous MnO2@Co3O4 composite from a MnOOH@ZIF-67 precursor, which is synthesized via a self-assembly strategy. The one-dimensional porous structure provided more active sites and shorter-ion/electron-diffusion distance, thereby enabling higher Li+ storage capacity and better rate capability than a transition metal oxide alone. The Co3O4 coating buffered the volume change during Li+ insertion/extraction, leading to increased cycling stability of the electrode. When evaluated as the anode of LIBs, MnO2@Co3O4 exhibited a reversible capacity of 647 mA h g−1 at 2000 mA g−1 after 400 cycles. This excellent performance indicated that the MnO2@Co3O4 material could be an attractive potential candidate for Li+ storage.
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高影响因子
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