bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies of Solid State Electrolytes for Li-Type Batteries
Authors: Pan Jian , Tutusaus Oscar , Shu Chan , Mohtadi Rana
Published: December 2024

Solid state electrolyte has been one of the most promising candidates for advanced batteries due to its higher energy density and higher safety. However, current highly conducting solid state electrolytes (SSEs) still suffer from challenges associated with their intrinsic properties.1 These challenges of interfacial issues related to instabilities to the electrode active materials can lead to cell failure. Herein, we have carefully examined common solid state electrolytes and showcase new type of solid state electrolytes that can overcome the existing challenges.

Reference:

O. Tutusaus, H. Kuwata, M. J. Counihan and R. Mohtadi, Chem. Commun., 59, 4746 (2023).
Charge-Discharge Performance of All-Solid-State Lithium Batteries with Amorphous MoS4 Electrodes Prepared By Thermal Decomposition of (NH4)2[Mo3S(S2)6]·H2o
Authors: Imai Keitaro , Shigedomi Tatsuki , Furukawa Tomohiro , Kowada Hiroe , Motohashi Kota , Sakuda Atsushi , Hayashi Akitoshi
Published: December 2024

All-solid-state lithium batteries with nonflammable inorganic solid electrolytes have attracted attention in terms of safety. Transition-metal sulfides are promising positive electrode active materials because of their relatively high electronic conductivities and capacities. Generally, higher specific capacities would be achieved by increasing the S content in transition-metal sulfide [1]. We have investigated electrochemical performance of all-solid-state cells using transition-metal sulfide active materials (TiS
x

[1−3], NbS
x

[4], MoS
x

[5,6] etc.). For example, amorphous molybdenum polysulfides exhibited higher capacities than MoS2 active materials by using anion redox reactions of sulfur [5,6].

In this study, amorphous MoS4 (a-MoS4) samples prepared by thermal decomposition of (NH4)2[Mo3S(S2)6]·H2O were applied to the electrode active materials for all-solid-state batteries. By XRD measurement, it was confirmed that amorphous materials were obtained through thermal decomposition of (NH4)2[Mo3S(S2)6]·H2O in an argon atmosphere. The molar ratio of S to Mo was determined to be 4 (MoS4) by CHNS elemental analysis. The Mo3d XPS spectrum of a-MoS4 indicated that the electronic state of Mo in a-MoS4 was close to that in MoS2. In the S2p XPS spectrum, two sets of doublet peaks were observed. Thus, in a-MoS4, sulfur would form the S-S bonds which enhance its capacity. The electronic conductivities of a-MoS4 measured by DC polarization were 5.0 × 10−4 S cm−1 at 25 ºC. Composite working electrodes were fabricated by mixing a-MoS4, Li3PS4 glass, and acetylene black (40 : 60 : 6 wt%). Li3PS4 glass and Li–In alloy were used as a solid electrolyte separator and a counter electrode, respectively. All-solid-state lithium cells using a-MoS4 active materials operated with a cut-off voltage of 0.9–2.2 V (vs. Li–In) at 25 ºC under a current density of 0.13 mA cm−2. The cells exhibited high reversible capacities of about 460 mAh g−1 for 150 cycles.

In conclusion, amorphous MoS4 active materials were successfully prepared by thermal decomposition of (NH4)2[Mo3S(S2)6]·H2O. All-solid-state cells (Li-In / Li3PS4 glass / a-MoS4) showed relatively high capacities and good cyclabilities.

References

[1] A. Sakuda et al., J. Am. Chem. Soc., 139 (2017) 8796–8799.

[2] A. Hayashi et al., Chem. Lett., 41 (2012) 886–888.

[3] A. Sakuda et al., Electrochem. Commun., 31 (2013) 71–75.

[4] A. Sakuda et al., ECS Electrochem. Lett., 3 (2014) A79.

[5] T. Matsuyama et al., J. Mater. Chem. A, 3 (2015) 14142–14147.

[6] G. Shirota et al., J. Ceram. Soc. Jpn., 130 (2022) 308–312.
Probing the Mechanical Properties of Superionic Boron Cluster Solid Electrolytes
Authors: Tutusaus Oscar , Hempel Jacob , Thapa Santosh , Kim Kwangnam , Kweon Kyoung E. , Wood Brandon C. , Hentz Luke , Hill Ryan Christopher , Mohtadi Rana , Cheng Yang-Tse
Published: December 2024

All-solid-state batteries (ASSB) are a promising alternative to their conventional liquid electrolyte-based counterparts due to their increased safety and their potential to achieve higher energy density. To achieve these goals, a ASSB requires a solid-state electrolyte (SSE) with high ionic conductivity near room temperature and high electrochemical stability. Lithium and sodium salts of boron cluster anions have attracted much attention as SSE candidates due to their high ionic conductivities (>103 S/cm) following a solid-phase transition into a disordered phase at relatively low temperatures (50-130°C) and relatively wide electrochemical window.[1]

In considering their application to ASSB, their mechanical properties also play a critical role due to the stresses the electrolyte material is subjected to during battery operation.[2] First-principle calculations have been instrumental so far to provide an initial assessment of bulk and elastic moduli for some selected boron cluster solid electrolytes,[3-5] but direct measurements are still lacking. Herein, we will report the first determination of elastic moduli and hardnesses of the most representative boron cluster salts using both nanoindentation continuous stiffness method (CSM) and ultrasound under inert atmosphere and compared with DFT calculations.

References

[1] R. Mohtadi et al., Nat.
Rev. Mater., 2, 16091 (2017)

[2] S. Kalnaus et al., Science, 381, eabg5998 (2023)

[3] H. Chen et al., J. Electrochem. Soc., 166, A493 (2019).

[4] Z. Lu et al., Chem. Mat., 29, 9308 (2017)

[5] R. Moury et al., Acta Crystallogr., Sect. B: Struct. Sci., 75, 406 (2019)
Synthesis and Characterization of BH4-Substituted Lithium Argyrodite for Assbs
Authors: Han JiHoon , Lee Young-Su , Yi Kyung-Woo , Cho Young Whan
Published: December 2024

In the present study, we have successfully synthesized BH4-substituted lithium argyrodites by dry ball milling as well as by wet mechanochemical processing. Simultaneous substitution of BH4 and Cl/Br/I for non-bridging sulfur in the argyrodite structure was also possible by ball milling. The ionic conductivity of these BH4-substituted argyrodite-type electrolytes exhibit a maximum conductivity of up to 16.4 mS/cm at 25°C in their cold-pressed state. We confirmed the composition and distribution of substituted ions in the crystal structure by XRD Rietveld refinement and investigated the movement of lithium ions and the substitution of BH4 by solid-state NMR. The thermal stability and decomposition product at high temperatures have also been analyzed by thermo-gravimetric analysis/mass spectrometry (TGA/MS) and XRD. To characterize the electrochemical properties of BH4-substituted argyrodite-type electrolytes, we have used various analytical tools such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Li symmetric cell, c-rate and long-term cycle tests of full cells with LiNbO3-coated NCM811 as a cathode, have also been done. The test results so far have shown very high ionic conductivity, excellent electrochemical stability and much higher critical current density compared with similar cells with commercial Li6PS5Cl as the electrolyte.

References

1. Y.-J. Jang, H. Seo, Y.-S. Lee, S. Kang, W. Cho, Y. W. Cho, J.-H. Kim, Lithium Superionic Conduction in BH4-Substituted Thiophosphate Solid Electrolytes. Adv. Sci. 2023, 10, 2204942.

2.Ji-Hoon Han, Do Kyung Kim, Young Joo Lee, Young-Su Lee, Kyung-Woo Yi and Young Whan Cho,
Mater. Horiz.
, 2024,11, 251-261. DOI: 10.1039/d3mh01450a
Growth of Solid Electrolyte Li1+X
Al
x
Ti2-X
(PO4)3 Single Crystals
Authors: Maruyama Yuki , Okanda Kohei , Nagao Masanori , Watauchi Satoshi , Tanaka Isao
Published: December 2024

The bulk single crystals are useful for our understanding of interfacial properties. Single crystals of lithium ion conductor, which can reveal intrinsic electrochemical properties, are an essential material for the development of high-performance all-solid-state lithium-ion secondary batteries. Li1+x
Al
x
Ti2-x
(PO4)3 (LATP) has a high ionic conductivity of ~10-3 S/cm at room temperature and show promise for the application of solid electrolyte for all solid-state batteries1, 2). We have tried to grow LATP crystals by floating zone method. Lithium phosphate such as Li4P2O7 evaporated from the molten zone during the crystal growth. As the result, AlPO4 and TiO2 phases precipitated in the LATP grown crystals. Therefore, excessive addition of lithium phosphate into the feeds to compensate for the evaporation component is necessary for LATP crystal growth. Next, we grew LATP crystals using the feed with a Li4P2O7 excess from the LATP composition by the melt slow cooling method. As the result, we have successfully grown LATP single crystals as shown in Fig 1, when the crystals were grown with a molar ratio of LATP : Li4P2O7 = 1 : 1, a maximum temperature of 1400°C, and a slow cooling rate of 5°C/h. The concentration of Al in the grown crystals was x = 0.16, which is approximately half of the feed concentration (x = 0.3). The crystal orientation was [100], and the ionic conductivity was σ[100] = 9.1 × 10-4 S/cm at room temperature.

Reference

1) H. Aono et al., J. Electrochem. Soc., 137, 4, 1023-1027 (1990).

2) Yihzou Zhu et al., J. Mater. Chem. A 4, 3253 (2016).

Figure 1
Operando Tomographic Imaging of Dendrite Initiation and Propagation in Lithium Metal Solid-State Batteries
Authors: Hu Bingkun , Ning Ziyang , Bruce Peter
Published: December 2024

The implementation of lithium-anode solid-state batteries (SSBs) faces a significant hurdle in the form of lithium dendrite growth within ceramic solid electrolytes (SEs) during charging at practical rates. Synchrotron X-ray computed tomography (XCT), with its high temporal and spatial resolutions and phase contrast, has emerged as a powerful tool for investigating dendrite-related issues. It offers non-destructive three-dimensional (3D) visualisation of interior structures, including pores and cracks, along with the precise positioning of deposited lithium. Recently, we have established methods and setups for operando tomographic imaging of SSBs, successfully elucidating dendrite initiation and propagation mechanisms1,2. Our findings have demonstrated that dendrite initiation and dendritic crack propagation are separate processes. Initiation occurs as a result of lithium deposition into subsurface pores. Subsequent charging increases pressure within the pores due to slow extrusion of lithium back to the surface, ultimately leading to cracking. Transverse cracks then propagate from the plated electrode to the stripped electrode through wedge opening, with deposited lithium driving the dry crack from the rear. The influences of electrolyte microstructures on dendrite penetration are examined. These understandings hold promise for advancing the development of dendrite-free SSBs through the rational design of SEs.

References

Z. Ning, et al. Visualizing Plating-Induced Cracking in Lithium-Anode Solid-Electrolyte Cells, Nature Materials, 20, 1121–1129 (2021).

Z. Ning, et al. Dendrite Initiation and Propagation in Lithium Metal Solid-State Batteries, Nature, 618, 287–293 (2023).
(Invited) Strain-Free Mxene Electrodes for All Solid-State Batteries
Authors: Okubo Masashi
Published: December 2024

All-solid-state batteries with non-flammable inorganic solid electrolytes are a key technology to address the safety issues of lithium-ion batteries with flammable organic liquid electrolytes. However, conventional electrode materials suffer from substantial volume change during lithium-ion (de)intercalation, leading to the failure of the interface between the electrode materials and solid electrolytes and then severe performance degradation. In this work, we report strain-free charge storage via an interface between a transition-metal carbide nanosheet (MXene) and solid electrolytes, where MXene shows negligible structural change during lithium-ion (de)intercalation. Combined assessment including operando STEM-EELS elemental mapping clarified the strain-free nature of the MXene electrodes in the all solid-state batteries. In addition, the irreversible reactions at the MXene-electrolyte interface is visualized, explaining the inital irreversible capacities and relatively low rate capability of the MXene electrodes. A strain-free all-solid-state battery, which consists of Ti3C2Tx anode and disordered rocksalt Li8/7Ti2/7V4/7O2 cathode, demonstrates a long-term operation owing to the strain-free nature of both electrode materials.
(Invited) All-Solid-State Lithium-Sulfur Batteries: From Cathode Architecture to Pouch Cell Engineering
Authors: Lin Yi , Scrudder Coby H. , Chen Hanjing , Yamakov Vesselin I , Kang Jin Ho , Su Ji , Ledesma Rodolfo I , Dornbusch Donald A , Viggiano Rocco P.
Published: December 2024

Future electric aircraft will be enabled by technologies for safe and high specific energy batteries. Solid-state batteries with non-flammable solid electrolyte are much safer than conventional lithium ion batteries with organic solvent-based liquid electrolytes. Lithium-sulfur (Li-S) chemistry is among the highest specific energy storage platforms. Therefore, it has been suggested that the all-solid-state Li-S system is a top candidate for aviation batteries. However, the challenges start with all components of the battery cells, such as the non-conductive sulfur as the cathode active material, low conductivity and poor stability of the solid electrolyte, and the lithium–solid electrolyte interface roughened with battery reactions. In addition, even after successful development of the cell components, further challenges begin with the scale up of individual component for larger format pouch cells, such as preparing large area cathode and solid electrolyte films and non-conventional pouch fabrication processes. In this presentation, we discuss our recent progress regarding the entire all-solid-state Li-S battery system, from cell component optimization to scale-up fabrication for pouch cells. Performance metrics of these high specific energy cells will be presented and perspectives for future aviation batteries will be provided.
Influence of the Sputtering and Annealing Conditions in the Obtained LiFePO4 Thin Film Cathodes
Authors: Lopez Pazos Elena , Nobili Luca , Magagnin Luca
Published: December 2024

The current development of microelectronics requires mature micro energy storage devices. Such devices include, among others, micro batteries. The working principle of such micro batteries does not differ from traditional batteries. However, there are some particular aspects that distinguish them. The first one is that organic liquid electrolytes should be avoided due to their flammability and risk of leakage. Additionally, a great attention must be paid to the energy density of the included materials, since the final aim is the miniaturization [1]. In this sense the use of thin film deposition techniques becomes crucial for micro batteries fabrication [2,3]. Among these techniques, sputtering constitutes an interesting choice, due to the possibility it offers to transfer the composition of a source target material to a substrate. As a result, thin compact layers with a well-controlled thickness can be obtained. Regarding the cathodic element of the battery, LiFePO4 thin film layers have been attracting some attention due to their compromise between cost, performance, and material availability [4]. In this study, LiFePO4 thin film cathodes have been sputtered on silicon wafers. Electrochemical characterization techniques (Cyclic Voltammetry and Charge-Discharge) have been combined with material characterization ones (XRD) with the aim of understanding how a potential contact with air during the deposition process could affect the amount of olivine LiFePO4 phase in the film, and, subsequently, the capacity of the cathodic layer. The obtained results have facilitated a better understanding of the material’s performance according to the obtained composition.

1]

L. Y. e. al, "On-Chip Batteries for Dust-Sized Computers," Advanced Energy Materials, vol. 12, p. 2103641, 2022.

[2]

B. J. Neudecker, N. J. Dudney and J. B. Bates, ""Lithium‐Free" Thin‐Film Battery with In Situ Plated Li Anode," J. Electrochem.
Soc., vol. 147, no. 517, 200.

[3]

T. Yamamoto, H. Iwasaki, Y. Suzuki, M. Sakakura, Y. Fujii, M. Motoyama and Y. Iriyama, "A Li-free inverted-stack all-solid-state thin film battery using crystalline cathode material," Electrochemistry Communications, vol. 105, 2019.

[4]

V. A. Sugiawati, F. Vacandio, C. Perrin-Pellegrino, A. Galeyeva, A. P. Kurbatov, T. Djenizian "Sputtered Porous Li-Fe-P-O Film Cathodes Prepared by Radio Frequency Sputtering for Li-ion Microbatteries" Scientific Reports, vol. 9, 2019.
Na-Ion Battery Based on Carbon and Phosphate Chemistries
Authors: Krajewski Michał , Grabowski Oskar , Chmielniak Marta , Winkowska-Struzik Magdalena , Czerwinski Andrzej
Published: December 2024

Lithium-ion batteries are one of the most used power sources in a variety of fields: microelectronics, portable devices, automotive or even stationary energy storage. The huge growth of the Li-ion battery market raises concerns about the limited availability of lithium resources and its rising cost of acquisition. To counteract that effect, scientists again focused on sodium, as a cheaper and easily acquirable element to use in electrochemical power sources [1, 2].

In principle, sodium-ion batteries operate through similar mechanisms as lithium-ion cells, where Na+ ions are charge carriers between negative and positive electrodes. Most of the electrode materials used in the Na-ion technology come from their widely used analogues in Li-ion systems. However, due to differences in ion transport, reaction kinetics and Solid Electrolyte Interphase layer composition, there is a need for extensive studies to be carried out before the wide commercialisation of Na-ion batteries can take place [2].

In this presentation, we show our results from research on Na-ion battery systems, based on carbon and phosphate chemistries. From the negative electrode side, carbonaceous materials prepared in our lab showed good capacities (ca. 200 mAh g-1), outstanding cyclability and high-rate performance (above 95% and 50% capacity retention during cyclability and high-rate tests, respectively). For the positive electrode, transition metal phosphates obtained through various synthetic routes also showed excellent performance (above 95% and 95% capacity retention during cyclability and high-rate tests, respectively) in Na-ion cells. Materials with the best electrochemical performances were used to construct a full Na-ion battery, which showed promising results in full-cell geometry and the feasibility of carbon and phosphate chemistries in the development of post-lithium battery systems.

Acknowledgements: This work was supported by The Polish National Centre of Science through a research grant 2021/43/D/ST5/01220 entitled “High-voltage sodium-ion batteries based on exfoliated graphite electrodes”.

Literature:

[1] Jamesh, M. I. & Prakash, A. S. J. Power Sources
378, 268–300 (2018).

[2] Delmas, C. Adv. Energy Mater.
8, 1–9 (2018).
Enhancing Rate Performance and Stability of Nickel Hexacyanoferrate through K+ Substitution for Na+ Guest Ions
Authors: Kang San Chun , Song Na Young , Chun Sang-Eun
Published: December 2024

Nickel hexacyanoferrate (NiHCF) is a promising cathode for aqueous Na-ion batteries, exhibiting excellent rate performance and stability due to its stable and 3D open structure. During the coprecipitation for NiHCF synthesis, H2O molecules are inevitably introduced into the structure occupying Fe sites or interstitial sites. The H2O coordinated to the Ni atom induces Fe vacancy, reducing capacity. Additionally, the interstitial H2O can hinder the movement of Na-ions intercalated into the NiHCF structure, impairing the rate capability. Accordingly, suppressing H2O formation during coprecipitation would enhance electrochemical performance by increasing the amount of redox-active Fe and allowing for rapid ion movement. This study aimed to minimize the H2O amount within the structure by employing more chelating agent and introducing guest ions causing less hydration during the synthesis.

The NiHCF samples were synthesized with varying concentrations of chelating agent (0.03 M, 0.1 M citrate ions) and different guest ions (Na+, K+). With more citrate ions, the enlarged cubic particles are formed with less water, inferring a higher crystallinity. The NiHCF sample with K+ guest ion instead of Na+ prepared at higher citrate ion concentration contains fewer Fe vacancies with the lowest H2O contents (Na0.02K1.59Ni[Fe(CN)6]0.96∙0.75H2O) compared to the NiHCF sample with Na+ with guest ion (Na1.59Ni[Fe(CN)6]0.93∙2.75H2O). The reduced H2O contents generated less Fe vacancy, inducing a highly crystalline structure among all samples. The lowest H2O amount is formed due to the high concentration of the chelating agent, which blocks the direct bonding of Ni with H2O during the coprecipitation. Furthermore, the lower hydration of K+ than Na+ leads to decreased H2O amount within the crystal. As a result, the improved capacity of 80 mAh g-1 at 0.1 A g-1 was obtained based on the reduced Fe vacancy. The enhanced stability of 83% capacity retention is achieved by lower H2O contents after 1,000 cycles at 1.0 A g-1. Additionally, the K-inserted NiHCF exhibits a higher rate performance of 82% (10 A g-1 vs. 0.1 A g-1) compared to 69% of the Na-inserted NiHCF (Fig. 1). The highly stable and high-rate NiHCF cathode can be synthesized with appropriate amount of chelating agent and selecting guest ion for aqueous Na-ion batteries.

Figure 1
On the Exploitation of Magnetic Fields in Zn-Ion Batteries
Authors: Bell Jeffrey Gordon
Published: December 2024

Owing to their high safety and low-cost, aqueous zinc-ion batteries (AZIBs) are proposed as being highly applicable in both portable and stationary energy storage. As such, AZIBs are among the most researched aqueous battery systems, although problems remain with the formation of zinc dendrites during plating on the anode. Another problem resulting in poor cyclability and less than desirable capacity retention is the unwanted cross-diffusion of various species. Common approaches to mitigate these problems include electrode engineering and incorporating additives and ion-selective membranes into the system for improving cycle life and coulombic efficiency. This talk will highlight the potential for generalizability in the incorporation of internally contained magnetic fields in various implementations of AZIBs. Focus will be placed on various redox chemistries, anode/cathode material, placement and strength of magnetic fields. Here we show that moderate internal magnetic fields are capable of simultaneously mitigating dendrite growth while drastically reducing cross-diffusion, leading to enhanced cycle life and improved energy and voltage efficiency.
Enhancing Electrochemical Performance through Anode Modification Strategies in Aqueous Zn Battery System
Authors: Cho Beom-Keun , Yu Seung-Ho
Published: December 2024

Commercial Li-ion batteries are widely applied in everyday life and industries, but there are some limitations in terms of low energy density/safety issues and unstable supply of resources. As an alternative to Li-ion batteries, aqueous Zn batteries have gained attention due to the abundance of Zn metal, low reduction potential (– 0.76 V vs. standard hydrogen electrode), and high theoretical capacity (820 mAh g–1) of multivalent Zn2+ ion.

However, the growth of Zn dendrites on anode surface and the formation of irreversible surface reaction byproducts poses challenges for ensuring long battery lifespan and commercialization. Common approaches to controlling performance degradation factors at the anode include functional surface coatings, electrolyte optimization, etc. In this presentation, we will discuss the effects of anode surface coating techniques and the effects of electrolyte additive conducted by our research group to enhance the performance of aqueous Zn batteries. We will elucidate the basis of our improvement strategies by conducting simultaneous (electro)chemical analyses. Additionally, we will introduce advanced techniques such as operando imaging/computational method to facilitate a comprehensive understanding of uniform Zn deposition.

The significance of the experimental results lies in the improved performance of aqueous Zn battery system by anode modification. We anticipate that the result will have a significant impact on the future development of aqueous Zn battery systems.

Figure 1
Addition Effect of Crown Ether on Intercalation of Solvated Mg2+ into Graphite Interlayers
Authors: Yamamoto Keito , Shimizu Masahiro
Published: December 2024

Rechargeable batteries with Mg ions as carrier ions have attracted much attention as one of a next-generation energy storage system.1−7 There have been few reports on the use of graphite as a negative electrode material. We have shown that the reversible capacity based on intercalation/deintercalation of solvated Mg2+ into/from graphite interlayers.8 In the formation of ternary graphite interlayer compounds (t-GICs) containing solvated Mg2+, the sizes of solvents and coordination ability associated with donor numbers and dielectric constant in electrolyte compositions should be significant.

In this study, we focused on the bulkiness of the solvated Mg2+. Crown ethers (12C4, 15C5, 18C6) with equimolar ratio to Mg2+ were added to electrolytes to capsulate and to control the overall sizes of the solvated ions. The solvation environments of the Mg2+ were characterized by using Raman spectroscopy. X-ray diffraction clearly represented the formation of t-GICs with a stage structure by using the electrolyte in which the ligand of Mg2+ was replaced to crown ether from the solvents. It was shown that reducing the bulkiness of the solvated Mg2+ facilitated the formation of t-GICs.

Acknowledgement

This work was supported by a Grant-in-Aid for Scientific Research (B) (20H02840) from the Japan Society for the Promotion of Science (JSPS).

References

J.-M. Tarascon, M. Armand, Nature, 414 (2001) 359.

D. Aurbach, Z. Lu, A. Schechter, Y. Gofe, H. Gizbar, R. Turgeman, Y. Cohen, M. Moshkovich, E. Levi, Nature, 407 (2000) 724.

H. D. Yoo, I. Shterenberg, Y. Gofer, G. Gershinsky, N. Pour, D. Aurbach, Energy Environ. Sci., 6 (2013) 2265.

J. Muldoon, C. B. Bucur and T. Gregory, Chem. Rev., 2014, 114, 11683–11720.

Y. Orikasa, T. Masese, Y. Koyama, T. Mori, M. Hattori, K. Yamamoto, T. Okado, Z. D. Huang, T. Minato, C. Tassel, J. Kim, Y. Kobayashi, T. Abe, H. Kageyama, Y. Uchimoto, Sci. Rep., 4 (2014) 5622.

R. Mohtadi, M. Matsui, T. S. Arthur, S. J. Hwang, Angew.
Chem. Int. Ed., 51 (2012) 9780.

T. Mandai, M. Watanabe, J. Mater. Chem. A, 11 (2023) 9755.

M. Shimizu, A. Nakahigashi, S. Arai, Phys. Chem. Chem. Phys., 23 (2021) 16981.
Electrochemical Solid Polymer Electrolyte Coating of Carbon Fibres for Structural Sodium Micro Batteries
Authors: Lind Elvira , Cattaruzza Martina , Zenkert Dan , Johansson Mats , Lindbergh Goran
Published: December 2024

Carbon fibre based structural batteries combine energy storage and mechanical load transfer into a single material. Multifunctional materials as such are attractive alternatives to today's state-of-the-art monofunctional batteries, particularly in mobile applications where the battery pack constitutes parasitic weight that decreases range. Structural batteries take advantage of carbon fibres’ ability to store electrochemical energy by insertion of alkali-ions and their outstanding mechanical properties, making them an inherently multifunctional material. A key aspect to structural batteries is an electrolyte that can transfer mechanical load and ions between the electrodes. A solid PEG-based solid polymer electrolyte (SPE) has been synthesised for Li chemistries in previous work, utilising electrochemical grafting to produce thin homogeneous films covering individual carbon fibres [1].

This method remains unexplored for Na based chemistries as an attractive, abundant and cheap alternative to Li. This paper demonstrates this single step, energy efficient electrochemical process to produce a chemisorbed, dense and homogeneous SPE around single carbon fibres for Na chemistries. Propylene glycol methyl ether acrylate is grafted and polymerised onto single fibres using sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) as supporting electrolyte. The synthesised SPE is characterised using various techniques and the electrochemical properties of the coated carbon fibre electrodes were investigated by cycling the electrodes in a battery setup. The results show a dense SPE that covers each individual fibre in a carbon fibre bundle and the electrodes cycle stably against Na metal with capacities that are on par with findings in previous work [2]. In a step towards realising single carbon fibre battery cells, this method holds the potential to produce fully solid state structural batteries, by using sustainable chemicals, that are scalable from micrometer dimensions and allow for novel battery design.

[1] Leijonmarck, S., Carlson, T., Lindbergh, G., Asp, L.E., Maples, H. and Bismarck, A., 2013. Solid polymer electrolyte-coated carbon fibres for structural and novel micro batteries. Composites Science and Technology, 89, pp.149-157.

[2] Harnden, R., Peuvot, K., Zenkert, D. and Lindbergh, G., 2018. Multifunctional performance of sodiated carbon fibers. Journal of The Electrochemical Society, 165(13), p.B616.
Revelation of Reaction and Capacity-Fading Mechanisms of Quasi-Solid-State Zn-Ion Batteries with δ-MnO2 As the Positive Active Material
Authors: Treerittiwittaya Weeraporn , Chinnakutti Karthik kumar , Tapia-Ruiz Nuria , Gao Hongyi , Kidkhunthod Pinit , Kasemchainan Jitti
Published: December 2024

Zinc-ion batteries (ZIBs) are widely researched and developed as favorable energy storage technologies thanks to their low cost, high safety, and availability towards mass production. When compared to typical liquid-based batteries, especially the water-based ones, quasi-solid-state batteries offer additional benefits including less corrosion, no gas evolution, no leakage and wider operating temperature range. The polymer electrolyte, combining poly(ethylene oxide) (PEO), Zn(OTf)2, and a minuscule quantity of Tetraethylene glycol dimethyl ether (TEGDME), is the key component of our quasi-solid-state batteries. The respective active materials of the positive and negative electrodes are δ-MnO2 and Zn. Note that cellulose nanofiber (CNF) is added as reinforcement in the polymer-electrolyte separator. We have assembled the batteries in a pouch cell and electrochemically tested by galvanostatic cycling at 10 mA·g-1. The first specific discharge capacity obtained is about 150 mAh·g-1. Then we have correlated the electrochemical reactions at δ-MnO2 involving Zn2+ and e- to its microstructural alteration by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and X-ray tomography. It was possible to observe that Mn in δ-MnO2 reduced its oxidation state from +4 to +3 after discharge and reversed to +4 after charge. Volume change of the δ-MnO2 particles during discharge and charge was also confirmed. Moreover, long-term cycling of the solid-state batteries, together with the microstructural analyses have been performed. After 100 cycles, the battery capacity remained less than 50 mAh·g-1. We have located the origin of such a capacity fading resulting from irreversible phase transformation of δ-MnO2 after interaction with Zn2+ and e-. This has opened our horizon to a new insight finding for comprehension of the mechanism within δ-MnO2 directly affecting the performances of solid-state ZIBs.
Complex-Type Fe-Cr Redox Flow Battery: Identification of Challenges
Authors: Zhou Xiaoyu , Hanafusa Kei , Tatsumi Ryota , Dong Yongrong , Moriuchi Kiyoaki
Published: December 2024

Long-Duration Energy Storages (LDES), with the ability to store excess energy generated by renewable sources such as solar and wind, play a vital role in ensuring a continuous and reliable power supply, which is crucial in promoting a more sustainable future. Redox flow batteries (RFBs) have attracted a great deal of attention as a highly suitable system for LDES, because of offering easy scalability, great flexibility by decoupling power and energy capacity, long cycle life, and enhanced safety. While all-vanadium RFBs are widely used as the most mature technology currently, for further market development, the research on novel RFB electrolytes aims to explore resource-unconstrained materials, such as titanium or manganese, that can achieve longer-duration capacity at reduced cost compared to vanadium [1][2].

Complex-type Fe-Cr materials have gained traction as RFB electrolytes due to their high electromotive force exceeding 1.6V [3]. In this report, we investigate KCrPDTA and K4[Fe(CN)6] aqueous solutions as electrolytes by conducting over 400 hours of charge-discharge operations in a RFB system with the total electrolyte volume of 6L, yielding excellent results including coulombic efficiency >99.9%, cell resistance of 0.95Ω・cm2, and energy density of 16.7 kWh/m3.

However, there are still several challenges to overcome for the practical application of these active materials. These identified challenges encompass limited solubility of positive electrolyte that restricts the energy density, serious pH stability of charged negative electrolyte, hydrogen generation due to the extremely low redox reaction potential, and issues with the current separator membranes.

[1] Y. Dong, et al. "A novel titanium/manganese redox flow battery." ECS Transactions 69.18 (2015): 59.

[2] H. Kaku, et al. "Enhanced performance of Ti/Mn redox flow battery." ECS Transactions 77.11 (2017): 173.

[3] B. Robb, et al. "Chelated chromium electrolyte enabling high-voltage aqueous flow batteries." Joule 3.10 (2019): 2503-2512.
Understanding the Multiple Roles of Solvation Structure in the Performance of Next-Generation Sodium Metal Battery Systems
Authors: Morris Louis Vincent , Pyles Cynthia , Dunkelberger Adam , Carter Rachel Elizabeth
Published: December 2024

Sodium metal batteries have become one of the most attractive targets for beyond-lithium electrochemical energy storage opportunities in recent years due to their low cost, high abundance, and sustainability when compared to popular lithium systems. The adoption of sodium metal batteries has been limited, however, by their instability and poor cycle life. Current efforts to resolve instability of the sodium metal anode have primarily focused on the adaptation of electrolyte systems (including solvents, salts, and additives) from the more researched lithium metal battery systems with some success.1 However, it has become clear that sodium metal batteries behave distinctly for their alkali counterpart, and will require new electrolyte design strategies. In order to inform solvation shell dynamics and SEI formation, this work explores 2 common salts (NaPF6 and NaTFSI) and 2 common solvents (diglyme and FEC) employed in sodium metal battery electrolytes. The selected components possess a range of desirable molecular structures bulk properties, allowing us to diagram the connections between their solvation structures and bulk solution phase properties. We achieve this by probing solvation shells with (1) Raman and (2) NMR spectroscopy, and following these chemical dynamics through to their impacts on electrolyte decomposition with in operando (3)electrochemical quartz crystal microbalance (EQCM) and SEI composition (4) XPS to morphology (5) SEM. Finally, we correlate these fundamental electrochemical and chemical observations to traditional cycling analysis as well as electrochemical impedance spectroscopy (EIS). We elucidate distinct roles of anion and solvent for ion transport and SEI formation in sodium systems, providing crucial understanding required for informed Na electrolyte design. 1. Sarkar, S.; Lefler, M.J.; Vishnugopi, B. Nuwayhid, R.B.; Love, C.T.; Carter. R.; Mukherjee, P.P.; Fluorinated ethylene carbonate as additive to glyme electrolytes for robust sodium solid electrolyte interface.
Cell Reports Physical Science
, 2023, 4, 101356.
Water-in-Salt Binary Mixtures: A Structural Analysis of Potassium Salts Derived Electrolyte
Authors: Dhasarathaboopathy Mukhilan , Palani Sabhapathy , Khokhar Vaishali , Gurkan Burcu E
Published: December 2024

The exploration of water-in-salt electrolytes has gained significant traction for high-voltage aqueous batteries, driven by their notable attributes including non-flammability, environmental sustainability, and an expanded potential window. This study focuses on synthesizing a novel water-in-salt binary mixture electrolyte tailored specifically for potassium-ion batteries, employing readily available and low-cost potassium salts. Through systematic blending of potassium acetate (KAc) and potassium trifluoromethane sulfonate (KOTf) at varying mole fractions, the aim was to optimize solubility while minimizing water activity. Our investigations led to the identification of K(Ac)0.9(OTf)0.1.1.5H2O as the most promising mixture, exhibiting exceptional solubility of 36.4 m, surpassing that of its individual constituents. Physical property assessments revealed remarkable characteristics, including a conductivity of 19.5 mS cm-1 and a viscosity of 73 mPa. s for the desired mixture, surpassing those observed in analogous water-in-salt binary mixtures. Raman spectroscopy investigations highlighted enhanced water-acetate interactions within the desired mixture, suggesting a correlation with its superior physical properties. Complementary In situ UV-VIS spectroscopy corroborated these findings, providing further insights into the electrolyte's structural dynamics. Electroanalytical techniques, including cyclic voltammetry and linear sweep voltammetry, were employed to elucidate the electrolyte's potential window, confirming its suitability for high-voltage applications. This study presents a high-concentration aqueous K-ion binary mixture characterized by exceptional ionic conductivity and a broad potential window, offering a promising avenue for advancing the development of robust and sustainable potassium-ion battery technologies.
Examing Competitive Coordination Structure in Eutectic Electrolyte for Zinc-Ion Batteries
Authors: Deng Wenjing , Wang Xiaolei
Published: December 2024

Designing next-generation alternative energy storage devices that feature high safety, low cost, and long operation lifespan is of the utmost importance for future wide range of applications. Aqueous zinc-ion batteries play a vital part in promoting the development of portability, sustainability, and diversification of rechargeable battery systems. Based on the theory of electrolyte solvation chemistry, deep understanding of interaction between electrolyte components and their impact on the chemical properties have significant influence on revitalizing the rechargeable zinc-ion batteries field. Characterized by intermolecular forces and tunable compositions, reorganized ligand-oriented solvation shell in eutectic system can bring potential benefits for Zn plating/stripping. Instead of forming [Zn(H2O)6]2+, the use of organic ligands in deep eutectic solvent electrolytes will allow the formation of multiple Zn coordination. In this case, we tentatively propose a plausible strategy to induce competing organic ligand for original eutectic electrolyte. The competing eutectic ligands enter coordination structure, weakening original interaction and form hydration-deficient complexes. The presence of competing agent enables the enhanced cation-anion binding. Building upon the competitive coordination, four-coordinated ligand-cation-anion cluster enables broadened electrochemical window, shielded active water and enhanced zincophilicity. The altered coordination further leads to robust hybrid organic-inorganic enriched solid electrolyte interphase, enabling passivated surface and suppressed dendrite growth. The in-depth mechanism is demonstrated by a series of excellent performance with high Coulombic efficiency and long working life. This design principle leveraged by eutectic electrolytes with competitive coordination offers a new approach to improve battery performance.
High-Capacity and Ultrastable Magnesium Batteries Enabled By Unique Solvation Reorganization in a Hybrid-Solvent Electrolyte
Authors: Chen Feiyang , Xu Zheng-Long
Published: December 2024

Rechargeable magnesium batteries (RMBs) are regarded as cost-effective candidates for lithium-ion batteries by virtue of the high earth abundance, high volumetric capacity, high safety, and low cost of Mg metal anodes. However, the lacking of suitable electrolytes compatible with high-capacity cathode and Mg anode hinders their further application. Herein, we present a novel hybrid-solvent electrolyte by mixing eco-friendly ethylene glycol (EG) and 1,2-dimethoxyethane (DME) solvents with Mg(TFSI)2 salt. The added EG significantly modifies the solvation structure of Mg2+ and establishes a rich hydrogen bonding network with DME solvent and TFSI- anions, which improves the overall physicochemical and electrochemical properties of the electrolyte. Therefore, the hybrid electrolyte exhibits a broad electrochemical window of ~3.85 V. As a demonstration material, VO2 nanorods are chosen as the cathode for the hybrid electrolyte, which could realize a reversible capacity of 257 mAh g-1, an ultra-long cycling stability over 1000 cycles with ultra-slow capacity decay rate of 0.0165 % per cycle at 500 mAg-1. More importantly, this electrolyte exhibits high compatibility with Mg metal. As a result, a reversible specific capacity of 278 mAh g-1 can be realized when assembled with Mg//VO2 full cells. The electrolyte design proposed in this work could provide an alternative approach to developing high-performance multivalent-ion batteries.
Development of High-Utilization Four-Electron Tin Anodes for Aqueous Batteries
Authors: Catalina Sofia K. , Wang Jianbo , Chueh William C. , Mefford Tyler
Published: December 2024

Developing high-energy density aqueous batteries is a vital step towards inexpensive and safe energy storage. A major challenge in this approach is achieving high utilization and reversibility with multi-electron metal anodes while operating near the water stability window. Of the main metal anode candidates (Zn, Al, Mg, Fe, Sn, etc.), Sn has recently received increasing attention due to its limited hydrogen evolution activity, dendrite-free plating, and high theoretical capacity for the four-electron Sn(OH)6
2-/Sn redox couple in alkaline electrolytes (903 mAh gSn
-1 or 6,560 Ah LSn
-1).

Understanding the reversibility of charge transfer processes that occur in aqueous batteries with metal anodes necessitates probing the solid, liquid, and gaseous phases that evolve during cycling. In this talk, we will discuss a robust toolbox of direct characterization tools developed to elucidate the electrochemical behavior of alkaline Sn batteries. Our work uncovers the origins of the kinetically asymmetric redox behavior, with direct four-electron plating during charging and discharge progressing in a stepwise 2+2 electron stripping through a Sn(OH)3
- intermediate.

The prolonged presence of the Sn(OH)3
- intermediate presents both challenges and opportunities with the alkaline Sn system. On the one hand, if crossover cannot be prevented, Sn(OH)3
- chemically reducing the cathode directly impacts coulombic efficiency. However, disproportionation of Sn(OH)3
- can be driven near the anode, improving voltage efficiency. Through understanding and controlling these effects, we engineer a four-electron Sn alkaline battery with high energy-efficiency, high utilization, and long cycle-life.
Electrochemical Characteristics of Rechargeable MnO
x
/Zn Battery
Authors: Fujimoto Hiroyuki , Yoshikawa Masaaki , Okada Masaki , Shimoda Keiji , Fujinami So , Morita Masayuki , Ogumi Zempachi , Abe Takeshi
Published: December 2024

The charge/discharge characteristics of several types of manganese oxides with different structures as positive electrodes for zinc negative electrode batteries were evaluated. It is said that MnOOH is formed in the discharge reaction of γ-MnO2, but when the charge/discharge reaction was performed using β-MnO2 as the positive electrode, the formation of Mn2O3 and Mn3O4 instead of MnOOH was observed in the first discharge reaction. After the second cycle, no reversible reformation of β-MnO2 due to charging was observed. Furthermore, due to the charge/discharge reaction, zinc was dissolved from the zinc negative electrode, and basic zinc compounds were observed as a by-product in both the positive and negative electrodes. After the second cycle, the amount of Mn2O3 and Mn3O4 produced increased and decreased each time the discharge and charge were repeated. The discharge capacity showed a stable discharge capacity of ca.200 Ahkg-1 until about 30 cycles, but after that it gradually decreased to 105 Ahkg-1 at 100 cycles.
Grid Synchronization of the VSC‐HVDC System Based on Virtual Synchronous Generator Control Strategy
Authors: Chethan M. , Kuppan Ravi
Published: December 2024

This paper explores an integration of virtual synchronous generators into voltage source converter–based VSC‐HVDC systems to enhance grid stability and performance. VSGs emulate the inertia and damping characteristics of traditional synchronous generators, thereby providing essential frequency support and improving transient stability during disturbances. The study focuses on design considerations, control strategies, and the impact of VSG incorporation on system dynamics. Through detailed simulations and analyses, it is demonstrated that VSGs can significantly reduce the rate of change of frequency during transient events, thus enhancing the overall robustness and reliability of VSC‐HVDC systems. In addition, the practical challenges of implementing VSG‐based control are addressed, and solutions are proposed to optimize system integration and performance.
Individual Diameter Growth Modeling of Terminalia alata (B. Heyne. ex Roth) in Terai Arc Landscape of Nepal
Authors: Gautam Pratima , Joshi Rajeev , Ayer Santosh , Gautam Jeetendra , Bhatta Kishor Prasad , Lamichhane Prakash
Published: December 2024

The development of a model is highly crucial in cases where there are intricate geographical features, and conducting a forest inventory is both time‐consuming and expensive, requiring significant manual effort for measurement. Acquiring reliable data regarding the forest’s condition and future progression is essential for making informed decisions about its management. Therefore, this research aimed to create an individual tree diameter growth model specifically for Terminalia alata (B. Heyne. ex Roth). This study was conducted in Terai Arc Landscape of Nepal, encompassing 14 districts in the Terai and Chure regions of Nepal. Individual tree data (diameter at breast height, tree height, crown height, crown cover, longitude, and latitude) from three different time periods (2011, 2017, and 2022) were obtained with 673 sample plots maintained for forest research assessment by Government of Nepal, and annual diameter growth was estimated. Multiple linear, linear mixed, and generalized additive models were employed to fit the growth modeling for individual tree diameter growth of T. alata. We observed higher mean diameter growth rates in 0–25 cm and 101–125 cm tree diameter classes (0.318 cm·yr−1). There were significant differences in diameter growth across tree quality classes, but no significant differences due to crown classes were observed. Although the generalized additive model (Adj. R2 = 0.32) performed better than the linear mixed model (adj. R2 = 0.23) and the multiple linear model (adj. R2 = 0.03), it still explained only a small proportion of the variance in diameter growth. This suggests that other factors, such as unmeasured environmental variables, biotic interactions, or complex nonlinear relationships, may play a significant role in explaining the variation. In addition, the low R2 values indicate that the models may need further refinement, possibly by incorporating interaction terms, random effects, or other possible nonlinear approaches. Future research should also consider the potential influence of spatial or temporal heterogeneity on the growth dynamics.