Energies

Research

9 pages, 1818 KiB

Open AccessArticle

Synthesis, Crystal Structure, and Ionic Conductivity of MgAl_2-xGa_xCl₈ and MgGa₂Cl₇Br

by Yasumasa Tomita, Ryo Saito, Ayaka Nagata, Yohei Yamane and Yoshiumi Kohno

Energies 2020, 13(24), 6687; https://doi.org/10.3390/en13246687 - 18 Dec 2020

Cited by 2 | Viewed by 2068

MgAl_2-xGa_xCl₈ and MgGa₂Cl₇Br was synthesized from MgCl₂, MgBr₂, AlCl₃, and GaCl₃, and the physical properties were evaluated by XRD, AC conductivity, and X-ray fluorescence. MgAl_2-x [...] Read more.

MgAl_2-xGa_xCl₈ and MgGa₂Cl₇Br was synthesized from MgCl₂, MgBr₂, AlCl₃, and GaCl₃, and the physical properties were evaluated by XRD, AC conductivity, and X-ray fluorescence. MgAl_2-xGa_xCl₈ has the same crystal structure as MgAl₂Cl₈, belongs to the space group C2/c, and forms a solid solution in all the synthesized compositions. We attempted to MgGa₂Cl_8-yBr_y synthesize in the same manner as MgAl₂Cl₈, but only obtained MgGa₂Cl₇Br as a single-phase compound. The AC conductivity of MgAl_2-xGa_xCl₈ was lowest for MgAl₂Cl₈ and highest for MgGa₂Cl₈. The conductivity of MgGa₂Cl₈ at 400 K was 1.7 × 10⁻⁶ S/cm. The conductivity of MgGa₂Cl₇Br was higher than that of MgAl_2-xGa_xCl₈ with a value of 1.6 × 10⁻⁵ S/cm at 400 K. The formation of Mg metal was observed at the surface of the cathode electrode in an experiment of flowing a direct current using an electrochemical cell, indicating that this compound is a magnesium ion conductor. Full article

(This article belongs to the Special Issue Novel Technologies for Metal-Ion and Metal Batteries)

► Show Figures

Figure 1

14 pages, 5361 KiB

Open AccessArticle

Probing the Effect of Titanium Substitution on the Sodium Storage in Na₃Ni₂BiO₆ Honeycomb-Type Structure

by Eugen Zemlyanushin, Kristina Pfeifer, Angelina Sarapulova, Martin Etter, Helmut Ehrenberg and Sonia Dsoke

Energies 2020, 13(24), 6498; https://doi.org/10.3390/en13246498 - 9 Dec 2020

Cited by 2 | Viewed by 1826

Abstract

Na₃Ni₂BiO₆ with Honeycomb structure suffers from poor cycle stability when applied as cathode material for sodium-ion batteries. Herein, the strategy to improve the stability is to substitute Ni and Bi with inactive Ti. Monoclinic Na₃Ni_2-x [...] Read more.

Na₃Ni₂BiO₆ with Honeycomb structure suffers from poor cycle stability when applied as cathode material for sodium-ion batteries. Herein, the strategy to improve the stability is to substitute Ni and Bi with inactive Ti. Monoclinic Na₃Ni_2-xBi_1-yTi_x+yO₆ powders with different Ti content were successfully synthesized via sol gel method, and 0.3 mol of Ti was determined as a maximum concentration to obtain a phase-pure compound. A solid-solution in the system of O3-NaNi_0.5Ti_0.5O₂ and O3-Na₃Ni₂BiO₆ is obtained when this critical concentration is not exceeded. The capacity of the first desodiation process at 0.1 C of Na₃Ni₂BiO₆ (~93 mAh g⁻¹) decreases with the increasing Ti concentration to ~77 mAh g⁻¹ for Na₃Ni₂Bi_0.9Ti_0.1O₆ and to ~82 mAh g⁻¹ for Na₃Ni_0.9Bi_0.8Ti_0.3O₆, respectively. After 100 cycles at 1 C, a better electrochemical kinetics is obtained for the Ti-containing structures, where a fast diffusion effect of Na⁺-ions is more pronounced. As a result of in operando synchrotron radiation diffraction, during the first sodiation (O1-P3-O’3-O3) the O’3 phase, which is formed in the Na₃Ni₂BiO₆ is fully or partly replaced by P’3 phase in the Ti substituted compounds. This leads to an improvement in the kinetics of the electrochemical process. The pathway through prismatic sites of Na⁺-ions in the P’3 phase seems to be more favourable than through octahedral sites of O’3 phase. Additionally, at high potential, a partial suppression of the reversible phase transition P3-O1-P3 is revealed. Full article

(This article belongs to the Special Issue Novel Technologies for Metal-Ion and Metal Batteries)

► Show Figures

Graphical abstract

19 pages, 5118 KiB

Open AccessArticle

Sustainable Anodes for Lithium- and Sodium-Ion Batteries Based on Coffee Ground-Derived Hard Carbon and Green Binders

by Hamideh Darjazi, Antunes Staffolani, Leonardo Sbrascini, Luca Bottoni, Roberto Tossici and Francesco Nobili

Energies 2020, 13(23), 6216; https://doi.org/10.3390/en13236216 - 26 Nov 2020

Cited by 28 | Viewed by 4129

Abstract

The reuse and recycling of products, leading to the utilization of wastes as key resources in a closed loop, is a great opportunity for the market in terms of added value and reduced environmental impact. In this context, producing carbonaceous anode materials starting [...] Read more.

The reuse and recycling of products, leading to the utilization of wastes as key resources in a closed loop, is a great opportunity for the market in terms of added value and reduced environmental impact. In this context, producing carbonaceous anode materials starting from raw materials derived from food waste appears to be a possible approach to enhance the overall sustainability of the energy storage value chain, including Li-ion (LIBs) and Na-ion batteries (NIBs). In this framework, we show the behavior of anodes for LIBs and NIBs prepared with coffee ground-derived hard carbon as active material, combined with green binders such as Na-carboxymethyl cellulose (CMC), alginate (Alg), or polyacrylic acid (PAA). In order to evaluate the effect of the various binders on the charge/discharge performance, structural and electrochemical investigations are carried out. The electrochemical characterization reveals that the alginate-based anode, used for NIBs, delivers much enhanced charge/discharge performance and capacity retention. On the other hand, the use of the CMC-based electrode as LIBs anode delivers the best performance in terms of discharge capacity, while the PAA-based electrode shows enhanced cycling stability. As a result, the utilization of anode materials derived from an abundant food waste, in synergy with the use of green binders and formulations, appears to be a viable opportunity for the development of efficient and sustainable Li-ion and Na-ion batteries. Full article

(This article belongs to the Special Issue Novel Technologies for Metal-Ion and Metal Batteries)

► Show Figures

Figure 1

12 pages, 3357 KiB

Open AccessArticle

Exploring the Charge Compensation Mechanism of P2-Type Na_0.6Mg_0.3Mn_0.7O₂ Cathode Materials for Advanced Sodium-Ion Batteries

by Chen Cheng, Manling Ding, Tianran Yan, Kehua Dai, Jing Mao, Nian Zhang, Liang Zhang and Jinghua Guo

Energies 2020, 13(21), 5729; https://doi.org/10.3390/en13215729 - 2 Nov 2020

Cited by 17 | Viewed by 3438

Abstract

P2-type sodium layered transition metal oxides have been intensively investigated as promising cathode materials for sodium-ion batteries (SIBs) by virtue of their high specific capacity and high operating voltage. However, they suffer from problems of voltage decay, capacity fading, and structural deterioration, which [...] Read more.

P2-type sodium layered transition metal oxides have been intensively investigated as promising cathode materials for sodium-ion batteries (SIBs) by virtue of their high specific capacity and high operating voltage. However, they suffer from problems of voltage decay, capacity fading, and structural deterioration, which hinder their practical application. Therefore, a mechanistic understanding of the cationic/anionic redox activity and capacity fading is indispensable for the further improvement of electrochemical performance. Here, a prototype cathode material of P2-type Na_0.6Mg_0.3Mn_0.7O₂ is comprehensively investigated, which presents both cationic and anionic redox behaviors during the cycling process. By a combination of soft X-ray absorption spectroscopy and electroanalytical methods, we unambiguously reveal that only oxygen redox reaction is involved in the initial charge process, then both oxygen and manganese participate in the charge compensation in the following discharge process. In addition, a gradient distribution of Mn valence state from surface to bulk is disclosed, which could be mainly related to the irreversible oxygen activity during the charge process. Furthermore, we find that the average oxidation state of Mn is reduced upon extended cycles, leading to the noticeable capacity fading. Our results provide deeper insights into the intrinsic cationic/anionic redox mechanism of P2-type materials, which is vital for the rational design and optimization of advanced cathode materials for SIBs. Full article

(This article belongs to the Special Issue Novel Technologies for Metal-Ion and Metal Batteries)

► Show Figures

Figure 1

14 pages, 2161 KiB

Open AccessFeature PaperArticle

Pulse Discharging of Sodium-Oxygen Batteries to Enhance Cathode Utilization

by Daniel Langsdorf, Timo Dahms, Valerie Mohni, Julian Jakob Alexander Kreissl and Daniel Schröder

Energies 2020, 13(21), 5650; https://doi.org/10.3390/en13215650 - 28 Oct 2020

Cited by 2 | Viewed by 1970

Abstract

Using sodium metal in sodium-oxygen batteries with aprotic electrolyte enables achieving a very high theoretical energy density. However, the promised values for energy density and capacity are not met in practical studies yet due to poor utilization of the void space in the [...] Read more.

Using sodium metal in sodium-oxygen batteries with aprotic electrolyte enables achieving a very high theoretical energy density. However, the promised values for energy density and capacity are not met in practical studies yet due to poor utilization of the void space in the cathode during battery discharge. In this work, we achieve better cathode utilization and higher discharge capacities by using pulse discharging. We optimize the chosen resting-to-pulse times, the applied current density, and elucidate that three-dimensional cathode materials yield higher capacities compared to two-dimensional ones. By implication, the pulse discharging mode ensures better supply with dissolved oxygen within the cathode. The higher amount of dissolved oxygen accumulated during the resting period after a current pulse is essential to form more of the discharge product, i.e., the metal oxide sodium superoxide. Interestingly, we show for the first time that the superoxide is deposited in a very unusual form of stacked and highly oriented crystal layers. Our findings on the pulse discharging can be transferred to other metal-oxygen battery systems and might assist in achieving their full potential regarding practical energy density. Full article

(This article belongs to the Special Issue Novel Technologies for Metal-Ion and Metal Batteries)

► Show Figures

Figure 1

13 pages, 2640 KiB

Open AccessArticle

Exploring Vinyl Polymers as Soft Carbon Precursors for M-Ion (M = Na, Li) Batteries and Hybrid Capacitors

by Afshin Pendashteh, Brahim Orayech, Jon Ajuria, María Jáuregui and Damien Saurel

Energies 2020, 13(16), 4189; https://doi.org/10.3390/en13164189 - 13 Aug 2020

Cited by 6 | Viewed by 2881

Abstract

The viability of the sodium-ion batteries as a post-lithium storage technology is strongly tied to the development of high-performance carbonaceous anode materials. This requires screening novel precursors, and tuning their electrochemical properties. Soft carbons as promising anode materials, not only for batteries, but [...] Read more.

The viability of the sodium-ion batteries as a post-lithium storage technology is strongly tied to the development of high-performance carbonaceous anode materials. This requires screening novel precursors, and tuning their electrochemical properties. Soft carbons as promising anode materials, not only for batteries, but also in hybrid capacitors, have drawn great attention, due to safe operation voltage and high-power properties. Herein, several vinyl polymer-derived soft carbons have been prepared via pyrolysis, and their physicochemical and sodium storage properties have been evaluated. According to the obtained results, vinyl polymers are a promising source for preparation of soft carbon anode materials for sodium-ion battery application. In addition, their applicability towards Li-ion battery and hybrid capacitors (e.g., Li ion capacitors, LICs) has been examined. This work not only contrasts the carbonization products of these polymers with relevant physicochemical characterization, but also screens potential precursors for soft carbons with interesting alkali metal-ion (e.g., Na or Li, with an emphasis on Na) storage properties. This can stimulate further research to tune and improve the electrochemical properties of the soft carbons for energy storage applications. Full article

(This article belongs to the Special Issue Novel Technologies for Metal-Ion and Metal Batteries)

► Show Figures

Figure 1

14 pages, 2984 KiB

Open AccessArticle

High-Capacity Dual-Electrolyte Aluminum–Air Battery with Circulating Methanol Anolyte

by Pemika Teabnamang, Wathanyu Kao-ian, Mai Thanh Nguyen, Tetsu Yonezawa, Rongrong Cheacharoen and Soorathep Kheawhom

Energies 2020, 13(9), 2275; https://doi.org/10.3390/en13092275 - 5 May 2020

Cited by 28 | Viewed by 6176

Abstract

Aluminum–air batteries (AABs) have recently received extensive attention because of their high energy density and low cost. Nevertheless, a critical issue limiting their practical application is corrosion of aluminum (Al) anode in an alkaline aqueous electrolyte, which results from hydrogen evolution reaction (HER). [...] Read more.

Aluminum–air batteries (AABs) have recently received extensive attention because of their high energy density and low cost. Nevertheless, a critical issue limiting their practical application is corrosion of aluminum (Al) anode in an alkaline aqueous electrolyte, which results from hydrogen evolution reaction (HER). To effectively solve the corrosion issue, dissolution of Al anode should be carried out in a nonaqueous electrolyte. However, the main cathodic reaction, known as oxygen reduction reaction (ORR), is sluggish in such a nonaqueous electrolyte. A dual-electrolyte configuration with an anion exchange membrane separator allows AABs to implement a nonaqueous anolyte along with an aqueous catholyte. Thus, this work addresses the issue of anode corrosion in an alkaline Al–air flow battery via a dual-electrolyte system. The battery configuration consisted of an Al anode | anolyte | anion exchange membrane | catholyte | air cathode. The anolytes were methanol solutions containing 3 M potassium hydroxide (KOH) with different ratios of water. An aqueous polymer gel electrolyte was used as the catholyte. The corrosion of Al in the anolytes was duly investigated. The increase of water content in the anolyte reduced overpotential and exhibited faster anodic dissolution kinetics. This led to higher HER, along with a greater corrosion rate. The performance of the battery was also examined. At a discharge current density of 10 mA·cm⁻², the battery using the anolyte without water exhibited the highest specific capacity of 2328 mAh/g_Al, producing 78% utilization of Al. At a higher content of water, a higher discharge voltage was attained. However, due to greater HER, the specific capacity of the battery decreased. Besides, the circulation rate of the anolyte affected the performance of the battery. For instance, at a higher circulation rate, a higher discharge voltage was attained. Overall, the dual-electrolyte system proved to be an effective approach for suppressing anodic corrosion in an alkaline Al–air flow battery and enhancing discharge capacity. Full article

(This article belongs to the Special Issue Novel Technologies for Metal-Ion and Metal Batteries)

► Show Figures

Graphical abstract

9 pages, 809 KiB

Open AccessCommunication

Effect of Salt Concentration, Solvent Donor Number and Coordination Structure on the Variation of the Li/Li⁺ Potential in Aprotic Electrolytes

by P. K. R. Kottam, S. Dongmo, M. Wohlfahrt-Mehrens and M. Marinaro

Energies 2020, 13(6), 1470; https://doi.org/10.3390/en13061470 - 20 Mar 2020

Cited by 7 | Viewed by 2892

Abstract

The use of concentrated aprotic electrolytes in lithium batteries provides numerous potential applications, including the use of high-voltage cathodes and Li-metal anodes. In this paper, we aim at understanding the effect of salt concentration on the variation of the Li/Li⁺ Quasi-Reference Electrode [...] Read more.

The use of concentrated aprotic electrolytes in lithium batteries provides numerous potential applications, including the use of high-voltage cathodes and Li-metal anodes. In this paper, we aim at understanding the effect of salt concentration on the variation of the Li/Li⁺ Quasi-Reference Electrode (QRE) potential in Tetraglyme (TG)-based electrolytes. Comparing the obtained results to those achieved using Dimethyl sulfoxide DMSO-based electrolytes, we are now able to take a step forward and understand how the effect of solvent coordination and its donor number (DN) is attributed to the Li-QRE potential shift. Using a revised Nernst equation, the alteration of the Li redox potential with salt concentration was determined accurately. It is found that, in TG, the Li-QRE shift follows a different trend than in DMSO owing to the lower DN and expected shorter lifespan of the solvated cation complex. Full article

(This article belongs to the Special Issue Novel Technologies for Metal-Ion and Metal Batteries)

► Show Figures

Figure 1

12 pages, 2759 KiB

Open AccessArticle

Solvent-Dictated Sodium Sulfur Redox Reactions: Investigation of Carbonate and Ether Electrolytes

by Huang Zhang, Thomas Diemant, Bingsheng Qin, Huihua Li, R. Jürgen Behm and Stefano Passerini

Energies 2020, 13(4), 836; https://doi.org/10.3390/en13040836 - 14 Feb 2020

Cited by 20 | Viewed by 3498

Abstract

Sulfur-based cathode chemistries are essential for the development of high energy density alkali-ion batteries. Here, we elucidate the redox kinetics of sulfur confined on carbon nanotubes, comparing its performance in ether-based and carbonate-based electrolytes at room temperature. The solvent is found to play [...] Read more.

Sulfur-based cathode chemistries are essential for the development of high energy density alkali-ion batteries. Here, we elucidate the redox kinetics of sulfur confined on carbon nanotubes, comparing its performance in ether-based and carbonate-based electrolytes at room temperature. The solvent is found to play a key role for the electrochemical reactivity of the sulfur cathode in sodium–sulfur (Na–S) batteries. Ether-based electrolytes contribute to a more complete reduction of sulfur and enable a higher electrochemical reversibility. On the other hand, an irreversible solution-phase reaction is observed in carbonate solvents. This study clearly reveals the solvent-dependent Na–S reaction pathways in room temperature Na–S batteries and provides an insight into realizing their high energy potential, via electrolyte formulation design. Full article

(This article belongs to the Special Issue Novel Technologies for Metal-Ion and Metal Batteries)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Novel Technologies for Metal-Ion and Metal Batteries

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (9 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI