Zhirong Zhao-Karger's research while affiliated with Karlsruhe Institute of Technology and other places

Publications (112)

Article
Multivalent batteries show promising prospects for next‐generation sustainable energy storage applications. Herein, we report a polytriphenylamine (PTPAn) composite cathode capable of highly reversible storage of tetrakis(hexafluoroisopropyloxy) borate [B(hfip)4] anions in both Magnesium (Mg) and calcium (Ca) battery systems. Spectroscopic and comp...
Article
Multivalent batteries show promising prospects for next-generation sustainable energy storage applications. Herein, we report a polytriphenylamine (PTPAn) composite cathode capable of highly reversible storage of tetrakis(hexafluoroisopropyloxy) borate [B(hfip)4] anions in both Magnesium (Mg) and calcium (Ca) battery systems. Spectroscopic and comp...
Article
Magnesium-based next-generation batteries are of great interest since magnesium is not only very abundant, which allows economic and sustainable applications, but also less prone to dendrite formation than many other metals. Together with the bivalency of the magnesium cations the resulting possibility to safely use a metal anode enables batteries...
Conference Paper
Among the numerous post-lithium battery systems, the magnesium-sulfur battery represents a promising candidate due to its high energy density, improved safety and abundance of the applied raw materials. However, despite intensive research and promising achievements in recent years, the Mg-S battery is still in its infancy facing fundamental challen...
Article
Full-text available
Rechargeable calcium batteries possess attractive features for sustainable energy-storage solutions owing to their high theoretical energy densities, safety aspects and abundant natural resources. However, divalent Ca-ions and reactive Ca metal strongly interact with cathode materials and non-aqueous electrolyte solutions, leading to high charge-tr...
Conference Paper
Among the various post-lithium battery systems, the magnesium-sulfur battery represents a promising candidate due to its high energy density, improved safety and abundance of the applied raw materials. The underlying mechanisms are similar to those of a lithium-sulfur cell - analogously facing the challenge of sulfur retention in the cathode to mit...
Article
Full-text available
Magnesium–Sulfur batteries are one of most appealing options among the post-lithium battery systems due to its potentially high energy density, safe and sustainable electrode materials. The major practical challenges are originated from the soluble magnesium polysulfide intermediates and their shuttling between the electrodes, which cause high over...
Article
Magnesium (Mg) batteries represent a promising candidate for energy-dense, sustainable and safe energy storage. However, the realization of practical Mg batteries remains challenging and advanced material design strategies are imperatively necessary. Herein, a novel magnesium tetrakis(hexafluoroisopropyloxy)borate-based non-corrosive gel polymer el...
Article
Magnesium (Mg) anode‐electrolyte interaction is not trivial and investigation of the interfacial process can be helpful for the development of Mg batteries. In this work, we studied the Mg metal anode cycled in a chloride (Cl)‐free magnesium tetrakis (hexafluoroisopropyloxy) borate electrolyte using a full‐cell configuration with TiS 2 model cathod...
Article
Magnesium-sulfur (Mg-S) battery is receiving much research attention because of its high theoretical energy density, low-cost and sustainable electrode materials. However, the major issues such as self-discharge, low sulfur utilization in cathode and magnesium anode passivation severely hamper the battery operation. In this study, spontaneous magne...
Article
The magnesium-sulfur battery represents a promising post-lithium system with potentially high energy density and improved safety. However, just as all metal-sulfur systems, it is plagued with the polysulfide shuttle leading to active material loss and surface layer formation on the anode. To gain further insights, the present study aims to shed lig...
Article
Magnesium batteries are one of the most promising post-lithium technologies. One of the main challenges preventing its commercialization is to find an efficient and safe electrolyte. The electrolyte, playing the role of the blood in a battery, interacts with all battery components and must be highly compatible with all of them. The development of C...
Conference Paper
The magnesium-sulfur battery is a promising candidate as post-lithium battery system due to its high energy density, improved safety and abundance of the applied raw materials. Its underlying mechanism is comparable to the lithium-sulfur system also facing the challenge of sulfur retention in the cathode to mitigate the polysulfide shuttle. In cont...
Article
Full-text available
Rechargeable magnesium batteries are gaining attention as promising candidates for large‐scale energy storage applications because of their potentially high energy, safety and sustainability. However, the development of Mg batteries is impeded by the lack of efficient cathode materials and compatible electrode‐electrolyte combinations. Herein, we d...
Article
Full-text available
The performance of rechargeable magnesium batteries is strongly dependent on the choice of electrolyte. The desolvation of multivalent cations usually goes along with high energy barriers, which can have a crucial impact on the plating reaction. This can lead to significantly higher overpotentials for magnesium deposition compared to magnesium diss...
Article
Simple magnesium salts with high electrochemical and chemical stability and adequate ionic conductivity represent a new-generation electrolyte for magnesium (Mg) batteries. Similar to other Mg electrolytes, the simple-salt electrolyte also suffers from high charge-transfer resistance on the Mg surface due to the adsorbed species in the solution. In...
Article
Full-text available
In article number 2100868, Zhirong Zhao‐Karger and co‐workers report the functionalization of a commercial separator with a polyoxovanadate/carbon composite that can effectively suppress the polysulfide shuttle effect in magnesium – sulfur batteries via the chemical interaction between the vanadate and sulfur species. This innovative strategy could...
Preprint
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Information about the potential environmental impacts of post-lithium batteries is scarce. For this reason, this work provides a prospective life-cycle assessment of a hypothetical commercial MgS battery based on primary information obtained for a prototype cell. The Mg-S battery is found to have a good environmental performance with potential to o...
Article
The Cover Feature shows the principle of using two‐dimensional MXenes as a polysulfide‐confining interlayer to prevent self‐discharge and improve sulfur utilization of Mg–S batteries. More information can be found in the Full Paper by H. Kaland et al.
Article
Metal–sulfur (Me–S) batteries are one of the most promising battery technologies and might even outperform future Li-ion batteries. However, these systems generally show a relatively fast capacity loss, low power density, and fast self-discharge. Furthermore, the underlying mechanisms are insufficiently understood, making it difficult to systematic...
Article
Full-text available
Development of practical rechargeable Mg batteries (RMBs) is impeded by their limited cycle life and rate performance of cathodes. As demonstrated herein, a copper-porphyrin with meso-functionalized ethynyl groups is capable of reversible two- and four-electron storage at an extremely fast rate (tested up to 53C). Reversible four-electron redox wit...
Article
Full-text available
The realization of sustainable and cheap Mg-S batteries depends on significant improvements in cycling stability. Building on the immense research on cathode optimization from Li-S batteries, we are the first to report a beneficial role of MXenes for Mg-S batteries. Through a facile, low-temperature vacuum-filtration technique, we report on several...
Article
As environmental concerns mostly drive the electrification of our economy and the corresponding increase in demand for battery storage systems, information about the potential environmental impacts of the different battery systems is required. However, this kind of information is scarce for emerging post-lithium systems such as the magnesium-sulfur...
Article
The need for energy storage technologies that meet the demands for safety, sustainability, and high energy density has spurred increased interests in rechargeable Mg batteries. However, verification of their potential remains hampered by the absence of practical components. Recently, an unconventional research direction that deviates from the mains...
Conference Paper
Regarding energy density, safety, cost, and sustainability rechargeable magnesium batteries are a very promising next-generation energy storage technology. However, the processes in the electrolyte and at the electrode surface are not yet properly understood. The bivalency of the magnesium cations leads to strong coulomb interactions with the anion...
Article
The high energy density conversion cathode material like sulfur (S) is promising in combination with Mg anode because of the high theoretical capacity (1672 mA h g ⁻¹ or 3459 mA h cm ⁻³ ), as well as their wide abundance and low cost. Magnesium/sulfur (Mg/S) batteries face drawbacks like large over potential between charge/discharge cycles, rapid c...
Article
Full-text available
The combination of sulfur (S) as cathode with a Mg anode is a promising approach for batteries because of the high theoretical capacity (1,672 mAh g-1) as well as the abundance and relatively low cost of these elements. However, up to now Mg/S batteries face serious drawbacks like a large overpotential between charge/discharge cycles, rapid capacit...
Cover Page
Full-text available
In article number 2001806, Zhirong Zhao‐Karger and co‐workers report room‐temperature rechargeable calcium–sulfur (Ca–S) batteries enabled by a stable and efficient Ca [B (hfip) 4] 2 electrolyte. The Ca–S batteries exhibit a cell voltage close to its thermodynamic value and good reversibility. The mechanism of the redox reactions in this new batter...
Conference Paper
The high energy density conversion cathode material like sulfur (S) is promising in combination with Mg anode because of the high theoretical capacity (1672 mA h g-1 or 3459 mA h cm-3), as well as their wide abundance and low cost. Magnesium/sulfur (Mg/S) batteries face drawbacks like large overpotential between charge/discharge cycles, rapid capac...
Conference Paper
Operando investigation of the polysulfide dissolution behavior in magnesium-sulfur batteries using UVVis spectroscopy and microscopy. The study focuses on different glymes as electrolyte solvent, namely monoglyme, diglyme and tetraglyme.
Article
Full-text available
Rechargeable metal–sulfur batteries show great promise for energy storage applications because of their potentially high energy and low cost. The multivalent‐metal based electrochemical system exhibits the particular advantage of the feasibility of dendrite‐free metal anode. Calcium (Ca) represents a promising anode material owing to the low reduct...
Article
Magnesium-sulfur (Mg-S) batteries represent a very promising emerging cell chemistry. However, developments in Mg-S batteries are in an early stage, and the system exhibits problems similar to those of early lithium-sulfur batteries (Li-S). The significant challenges are the low coulombic efficiency and short cycle life of Mg-S batteries, mainly as...
Conference Paper
Since the first reported magnesium-sulfur (Mg-S) cell by Kim et al. in 2011 interest in this postlithium battery system has steadily increased due to its promising properties in regards of volumetric energy density, safety and costs. In recent years many research groups have attempted to unveil the underlying electrochemical mechanisms by sophistic...
Article
Full-text available
The choice of electrolyte has a crucial influence on the performance of rechargeable magnesium batteries. In multivalent electrolytes an agglomeration of ions to pairs or bigger clusters may affect the transport in the electrolyte and the reaction at the electrodes. In this work we include the formation of clusters in our general model for magnesiu...
Article
The present study aims to fundamentally understand the magnesium-sulfur battery and the interfacial processes involved. Therefore, electrochemical impedance spectroscopy (EIS) was carried out on symmetrical Mg/Mg and S/S cells as well as on full Mg/S cells. Besides the electrochemical behavior at the open-circuit voltage (OCV), the impedance evolut...
Article
Full-text available
Intense research efforts in electrochemical energy storage are being devoted to multivalent ion technologies in order to meet the growing demands for high energy and low‐cost energy storage systems. However, the development of multivalent metal (such as Mg and Ca) based battery systems is hindered by lack of suitable cathode chemistries that show w...
Article
Full-text available
Put into storage : Cathodes allowing fast cation mobility are demonstrated in a VS4 structure for high‐energy, multivalent (Mg and Ca) batteries. The flexible VS4 electronic structure enables cationic and anionic redox processes with multi‐electron transfer. Abstract The development of multivalent metal (such as Mg and Ca) based battery systems is...
Article
Rechargeable potassium‐ion batteries (KIBs) are promising alternatives to lithium ion batteries for large‐scale electrochemical energy storage application owing to the abundance and low cost of potassium resources. However, the development of KIBs is hampered by the lack of stable and high‐capacity cathode materials. Herein, a functionalized porphy...
Article
The present study shows the electrochemical performance of a room-temperature magnesium/sulfur (Mg/S) battery with a newly designed sulfur (3–0.5 mgsulfur cm−2) composite cathode. Operando Raman spectroscopy is employed to investigate the formation of polysulfide species at the cathode of Mg/S cells during the charge/discharge process, while densit...
Chapter
Although lithium-ion batteries (LIBs) dominate the market for rechargeable batteries, alternative chemistries are under investigation to develop new batteries, so-called “post-lithium” systems. Among these alternatives, magnesium rechargeable batteries (MRBs) are considered promising, because they use low cost, abundant materials and offer potentia...
Article
Full-text available
Rechargeable calcium (Ca) batteries have the prospect of high-energy and low-cost. However, the development of Ca batteries is hindered due to the lack of efficient electrolytes. Herein, we report novel calcium tetrakis(hexafluoroisopropyloxy) borate Ca[B(hfip)4]2 based electrolytes exhibiting reversible Ca deposition at room temperature, a high ox...
Article
Understanding Structure Changes during Cycling of MoS2-based Mg Batteries - Volume 25 Supplement - Xiaoke Mu, Zhenyou Li, Zhirong Zhao-Karger, Maximilian Fichtner, Christian Kübel
Article
Halogenid-basierte Materialien sind wichtige Bestandteile von Hochleistungselektroden und erlauben stabile Elektroden-Elektrolyt-Grenzflächen in Lithiumionenbatterien sowie neuartigen Batterietypen wie Magnesium-, Aluminium-, Halogenid-, Metallhalogen- und Flüssigmetall-Batterien. Der Wissensstand bei Halogenid-basierten Materialien wird zusamengef...
Article
Rechargeable batteries have been considered one of the most effective energy storage technologies bridging the renewable energy production and consumption. The further development of rechargeable batteries with characteristics such as high energy density, low cost, safety and a long cycle life is required to meet the ever‐increasing energy storage...
Article
Full-text available
Porphyrin complexes are well‐known for their application in solar cell systems and as catalysts, however, their use in electrochemical energy storage applications has only scarcely been studied. We report on the use of a tetra‐alkenyl substituted [5,10,15,20‐tetra(ethynyl)porphinato]copper(II) (CuTEP) complex as anode material in a high‐performance...
Article
Full-text available
Organic materials are both environmentally and economically attractive as potential electrode candidates. This Research News reports on a new class of stable and electrically conductive organic electrodes based on metal porphyrins with functional groups that are capable of electrochemical polymerization, rendering the materials promising for electr...
Article
Transition metal dichalcogenides have been considered as promising conversion-type electrode materials in sodium ion batteries, which allow multi-electron redox processes providing high capacities. However, the conversion reaction often leads to dramatic structural degradation of the electrodes during de-/sodiation, which strongly limits their cycl...
Article
Rechargeable magnesium (Mg) batteries (RMBs) are potential candidates for new generation battery technologies due to the attractive properties of Mg as a metal anode, especially the intrinsic nature of homogeneous Mg deposition and abundant Mg reserves. Compared to the monovalent counterpart (e.g. Li ⁺ ), the divalent Mg ions have a greater charge...
Article
Full-text available
Recently, the ternary spinel chalcogenide MgSc2Se4 was proposed to be a promising solid‐state electrolyte in rechargeable Mg batteries. In order to test the properties of the material, we use a modified solid‐state reaction to synthesize pure MgSc2Se4. Electrochemical characterizations identify detrimental high electronic conductivities, which limi...
Article
Full-text available
Rechargeable magnesium (Mg) batteries are an attractive candidate for next-generation battery technology because of their potential to offer high energy density, low cost, and safe use. Despite recent substantial progress achieved in the development of efficient electrolytes, identifying high-performance cathode materials remains a bottleneck for t...
Article
Full-text available
Quasielastic neutron scattering was used to investigate the low energy transfer dynamics of the complex borohydrides Mg(BH4)2 in the α- and β-modifications, LiBH4 in the low and high temperature crystal structure, and the 1:1 molar mixture of LiBH4+α-Mg(BH4)2. All investigated compounds show a rich dynamic behaviour below an energy range of ΔE = 10...
Article
Full-text available
Rechargeable magnesium batteries are one of the most promising candidates for next-generation battery technologies. Despite recent significant progress in the development of efficient electrolytes, an on-going challenge for realization of rechargeable magnesium batteries remains to overcome the sluggish kinetics caused by the strong interaction bet...
Conference Paper
The combination of magnesium and sulfur in an electrochemical cell is a promising candidate to cope the need of high-energy batteries for future applications like electric vehicles. Due to the abundance and non-toxicity of both elements it is not only a low cost and environmentally friendly couple but also ensures safety as magnesium offers dendrit...
Article
Rechargeable magnesium (Mg) battery has been considered as a promising candidate for future battery generations due to unique advantages of Mg metal anode. The combination of Mg with a sulfur cathode is one of the attractive electrochemical energy storage systems that use safe, low-cost and sustainable materials and could potentially provide a high...