scholarly journals Addition of Calcined Na2B4O7 on the Synthesis of Li7La3Zr2O12

2021 ◽  
Vol 24 (3) ◽  
pp. 77-84
Author(s):  
Imam Shofid Alaih ◽  
Sidiq Fathonah ◽  
Khoirina Dwi Nugrahaningtyas ◽  
Fitria Rahmawati

Li7La3Zr2O12 (LLZO) is a garnet-type electrolyte for all-solid-state lithium-ion batteries (ASSB). It has good chemical and electrochemical stability against lithium and a relatively high ionic conductivity. However, the ionic conductivity needs to be further increased to provide a high specific capacity of the ASSB. Element doping into LLZO is an effort to increase molecular defect, known to enhance the conductivity. This research studied the effect of the Na2B4O7 addition on the LLZO synthesis, producing LLZBO(A). The investigation aims to understand whether the sodium ions dope into the LLZO structure during synthesis, or it is only B ions to enter into the structure. Therefore, another synthesis with B2O3 of B precursor was conducted for comparison (LLZBO(B)). The precursors were mixed stoichiometrically by following the formula of Li7-xLa3-xZr2-xBxNaxO12 (LLZBO, x= 0.15; 0.20; 0.30). XRD analysis equipped with Le Bail refinement found that LLZBO(A) and LLZBO(B) mainly consist of cubic and tetragonal LLZO with a %mol of 69.06 – 69.84 %, and the main secondary phase is La2Zr2O7. The surface morphology of LLZBO(A) and LLZBO(B) is almost similar to the irregular form of large aggregates. The particles become more dispersed when 0.3 %mol dopant was submitted. Impedance analysis found a high ionic conductivity of LLZBAO(A)0.3 1.042x10-3 Scm-1.

2016 ◽  
Vol 34 (3) ◽  
pp. 605-616 ◽  
Author(s):  
K. Vijaya Babu ◽  
V. Veeraiah

AbstractThe most attractive property of Li0.5La0.5TiO3 (LLTO) electrolytes is their high ionic conductivity. Studies have shown that LLTO is capable of existing in a state with an ionic conductivity of 10-3 S/cm, which is comparable to liquid electrolytes. In addition to the high ionic conductivity of the material, LLTO is electrochemically stable and able to withstand hundreds of cycles. So, the studies of the solid electrolyte material are very important for the development of lithium-ion batteries. In the present paper, Li0.5La0.5Ti1-xZrxO3 (x = 0.05 and 0.1) have been prepared by a solid-state reaction method at 1300 °C for 6 hours to improve electrolyte materials for lithium-ion batteries. The phase identified by X-ray diffractometry and crystal structure corresponds to pm3m (2 2 1) space group (Z = 1). The frequency and temperature dependence of impedance, dielectric permittivity, dielectric loss and electric modulus of the Li0.5La0.5Ti1-xZrxO3 (x = 0.05 and 0.1) have been investigated. The dielectric and impedance properties have been studied over a range of frequency (42 Hz to 5 MHz) and temperatures (30 °C to 100 °C). The frequency dependent plot of modulus shows that the conductivity relaxation is of non-Debye type.


Membranes ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 45 ◽  
Author(s):  
Jahaziel Villarreal ◽  
Roberto Orrostieta Chavez ◽  
Sujay A. Chopade ◽  
Timothy P. Lodge ◽  
Mataz Alcoutlabi

In the present work, the effect of temperature and additives on the ionic conductivity of mixed organic/ionic liquid electrolytes (MOILEs) was investigated by conducting galvanostatic charge/discharge and ionic conductivity experiments. The mixed electrolyte is based on the ionic liquid (IL) (EMI/TFSI/LiTFSI) and organic solvents EC/DMC (1:1 v/v). The effect of electrolyte type on the electrochemical performance of a LiCoO2 cathode and a SnO2/C composite anode in lithium anode (or cathode) half-cells was also investigated. The results demonstrated that the addition of 5 wt.% succinonitrile (SN) resulted in enhanced ionic conductivity of a 60% EMI-TFSI 40% EC/DMC MOILE from ~14 mS·cm−1 to ~26 mS·cm−1 at room temperature. Additionally, at a temperature of 100 °C, an increase in ionic conductivity from ~38 to ~69 mS·cm−1 was observed for the MOILE with 5 wt% SN. The improvement in the ionic conductivity is attributed to the high polarity of SN and its ability to dissolve various types of salts such as LiTFSI. The galvanostatic charge/discharge results showed that the LiCoO2 cathode with the MOILE (without SN) exhibited a 39% specific capacity loss at the 50th cycle while the LiCoO2 cathode in the MOILE with 5 wt.% SN showed a decrease in specific capacity of only 14%. The addition of 5 wt.% SN to the MOILE with a SnO2/C composite-fiber anode resulted in improved cycling performance and rate capability of the SnO2/C composite-membrane anode in lithium anode half-cells. Based on the results reported in this work, a new avenue and promising outcome for the future use of MOILEs with SN in lithium-ion batteries (LIBs) can be opened.


2013 ◽  
Vol 1496 ◽  
Author(s):  
Sumaletha Narayanan ◽  
Lina Truong ◽  
Venkataraman Thangadurai

ABSTRACTGarnet-type electrolytes are currently receiving much attention for applications in Li-ion batteries, as they possess high ionic conductivity and chemical stability. Doping the garnet structure has proved to be a good way to improve the Li ion conductivity and stability. The present study includes effects of Y- doping in Li5La3Nb2O12 on Li ion conductivity and stability of “Li5+2xLa3Nb2-xYxO12” (0.05 ≤ x ≤ 0.75) under various environments, as well as chemical stability studies of Li5+xBaxLa3-xM2O12 (M = Nb, Ta) in water. “Li6.5La3Nb1.25Y0.75O12” showed a very high ionic conductivity of 2.7 х 10−4 Scm−1 at 25 °C, which is comparable to the highest value reported for garnet-type compounds, e.g., Li7La3Zr2O12. The selected members show very good stability against high temperatures, water, Li battery cathode Li2CoMn3O8 and carbon. The Li5+xBaxLa3-xNb2O12 garnets have shown to readily undergo an ion-exchange (proton) reaction under water treatment at room temperature; however, the Ta-based garnet appears to exhibit considerably higher stability under the same conditions.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Revannath Dnyandeo Nikam ◽  
Myonghoon Kwak ◽  
Jongwon Lee ◽  
Krishn Gopal Rajput ◽  
Writam Banerjee ◽  
...  

AbstractAll solid-state lithium-ion transistors are considered as promising synaptic devices for building artificial neural networks for neuromorphic computing. However, the slow ionic conduction in existing electrolytes hinders the performance of lithium-ion-based synaptic transistors. In this study, we systematically explore the influence of ionic conductivity of electrolytes on the synaptic performance of ionic transistors. Isovalent chalcogenide substitution such as Se in Li3PO4 significantly reduces the activation energy for Li ion migration from 0.35 to 0.253 eV, leading to a fast ionic conduction. This high ionic conductivity allows linear conductance switching in the LiCoO2 channel with several discrete nonvolatile states and good retention for both potentiation and depression steps. Consequently, optimized devices demonstrate the smallest nonlinearity ratio of 0.12 and high on/off ratio of 19. However, Li3PO4 electrolyte (with lower ionic conductivity) shows asymmetric and nonlinear weight-update characteristics. Our findings show that the facilitation of Li ionic conduction in solid-state electrolyte suggests potential application in artificial synapse device development.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jingnan Feng ◽  
Li Wang ◽  
Yijun Chen ◽  
Peiyu Wang ◽  
Hanrui Zhang ◽  
...  

AbstractCompared with traditional lead-acid batteries, nickel–cadmium batteries and nickel-hydrogen batteries, lithium-ion batteries (LIBs) are much more environmentally friendly and much higher energy density. Besides, LIBs own the characteristics of no memory effect, high charging and discharging rate, long cycle life and high energy conversion rate. Therefore, LIBs have been widely considered as the most promising power source for mobile devices. Commonly used LIBs contain carbonate based liquid electrolytes. Such electrolytes own high ionic conductivity and excellent wetting ability. However, the use of highly flammable and volatile organic solvents in them may lead to problems like leakage, thermo runaway and parasitic interface reactions, which limit their application. Solid polymer electrolytes (SPEs) can solve these problems, while they also bring new challenges such as poor interfacial contact with electrodes and low ionic conductivity at room temperature. Many approaches have been tried to solve these problems. This article is divided into three parts to introduce polyethylene oxide (PEO) based polymer-ceramic hybrid solid electrolyte, which is one of the most efficient way to improve the performance of SPEs. The first part focuses on polymer-lithium salt (LiX) matrices, including their ionic conduction mechanism and impact factors for their ionic conductivity. In the second part, the influence of both active and passive ceramic fillers on SPEs are reviewed. In the third part, composite SPEs’ preparation methods, including solvent casting and thermocompression, are introduced and compared. Finally, we propose five key points on how to make composite SPEs with high ionic conductivity for reference.


Sign in / Sign up

Export Citation Format

Share Document