Energy storage devices; electrocatalysis, materials for green energy
28
Scopus Publications
1307
Scholar Citations
17
Scholar h-index
24
Scholar i10-index
Scopus Publications
Effect of Silicon-Based Electrolyte Additive on the Solid-Electrolyte Interphase of Rechargeable Mg Batteries Shivaraju Guddehalli Chandrappa, Guruprakash Karkera, Sirshendu Dinda, Mario Löw, Holger Euchner, et al. Advanced Science, 2026 The unstable solid‐electrolyte interface (SEI) poses a major obstacle to the widespread use of rechargeable magnesium batteries (RMBs) as high‐volumetric‐capacity next‐generation energy storage systems. This issue is effectively mitigated by adding 3 wt.% tris(trimethylsilyl) borate (TMSB, C9H27BO3Si3) to a state‐of‐the‐art Cl‐free magnesium tetrakis(hexafluoroisopropyloxy)borate in dimethoxyethane (Mg[B(hfip) 4 ] 2 /DME) non‐aqueous electrolyte. The modified electrolyte enables stable Mg||Mo 6 S 8 (Chevrel phase, CP) full cell operation for up to 1000 cycles at a 1C rate. Tip‐enhanced Raman spectroscopy (TERS) reveals that TMSB scavenges degraded electrolyte components and facilitates the formation of a uniform and thin SEI on the magnesium anode. Reflection anisotropy spectroscopy (RAS) further demonstrates that TMSB transforms the interfacial structure, creating a more isotropic and robust SEI during the initial stripping and plating process, thereby extending electrochemical cycling stability. This approach presents a compelling pathway for practical RMB development by stabilizing the SEI and optimizing magnesium electrolyte formulations.
Cobalt Borate Complex With Tetrahedrally Coordinated Co2+- Promotes Lithium Superoxide Formation in Li-O2 Batteries Shivaraju G. Chandrappa, Katrin Forster‐Tonigold, Vasantha A. Gangadharappa, Pavithra Kannan, Kunkanadu R Prakasha, et al. Small, 2025 The development of non‐aqueous lithium‐oxygen (Li‐O2) batteries is hindered by inefficient discharge product decomposition, side reactions with the electrolyte, and high charge overpotentials (>1 V). This study explores the use of sodium cobalt borate (Na3CoB5O10, NCBO) with cobalt in tetrahedral geometry as an oxygen electrocatalyst for non‐aqueous Li‐O2 batteries. The prepared cobalt borate exhibits an oxygen evolution reaction (OER) overpotential of 326 mVRHE at a current density of 10 mA cm−2 and a Tafel slope of 42 mV dec−1 in 1 m KOH. Density Functional Theory (DFT) calculations identify the OH‐covered (101) surface of NCBO as the preferred OER site, with an overpotential between 451 and 544 mV. In Li‐O2 batteries, the NCBO cathode demonstrates 200 cycles with an overpotential of 1.95 V and 56.00% round‐trip efficiency at a capacity limit of 500 mA h g−1, along with a smaller charge overpotential of 0.64 V at a capacity limit of 2000 mA h g−1. Post‐cycling analysis of NCBO electrodes reveals electronically conductive Lithium Superoxide (LiO2) as the dominant discharge product. As revealed by DFT studies, the promising performance of NCBO in Li‐O2 batteries is attributed to its tetrahedral Co coordination, highlighting its potential for electrocatalytic applications.
Influence of In-Doping on the Structure and Electrochemical Performance of Compositionally Complex Garnet-Type Solid Electrolytes Alaa Alsawaf, Guruprakash Karkera, Thomas Diemant, Monaha Veerraju Kante, Yannik Schneider, et al. Small Structures, 2025 The electrochemical instability of electrode active materials as well as the flammability of the organic liquid electrolytes in Li‐ion batteries pose challenges for their safety and long cycle life. Solid electrolytes (SEs) that exhibit high ionic conductivity and a wide electrochemical stability window alleviate these challenges. Garnet‐type Li7La3Zr2O12 is a promising SE for next‐generation all‐solid‐state batteries. Herein, samples are prepared via a modified solid‐state reaction of compositionally complex Li6.3+zLa3Zr1.1−z Nb0.8Gd0.1InzO12 under different sintering atmospheres. X–ray diffraction patterns and Raman spectra prove the formation of a cubic garnet structure. Significant morphological changes are detected upon In‐doping and correlated to the ionic conductivity. The total Li‐ion conductivity of the dense pellets reaches 1 mS cm−1, among the highest reported to date, with an activation energy of 0.38 eV for the macroscopic ion transport obtained by impedance spectroscopy and as low as 0.24 eV for local Li‐ion hopping processes determined by 7Li nuclear magnetic resonance spin‐lattice relaxation measurements. The electronic contribution to the conductivity is negligible (10−10 S cm−1) making this compositionally complex SE a suitable candidate for all‐solid‐state battery applications.
Synthesis, Structural Analysis, and Degradation Behavior of Potassium Tin Chloride as Chloride-Ion Batteries Conversion Electrode Material Soutam Panja, Yidong Miao, Johannes Döhn, Jaehoon Choi, Simon Fleischmann, et al. Advanced Functional Materials, 2025 Chloride–ion batteries (CIBs) offer a compelling alternative to conventional battery systems, particularly in applications demanding cost‐effectiveness and resource sustainability. However, the development of tailored electrode materials remains a critical bottleneck for CIB advancement. In this study, an untapped class of perovskite‐based material, potassium hexachlorostannate (K2SnCl6, denoted as KSC) is synthesized via a facile mechanochemical route for the first time. The prepared KSC is subjected to various characterization techniques to confirm its crystal structure and morphology. Herein, KSC exhibits intriguing electrochemical performance in a non‐aqueous CIB configuration, utilizing a lithium metal counter electrode. Furthermore, ex situ X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS) analysis, reveal a conversion reaction mechanism involving chloride ion shuttling and provide insights into structural evolution during cycling. Moreover, the density functional theory (DFT) studies support additional degradation products that can potentially limit the performance of these materials as potential battery electrodes in CIBs.
Layered high-entropy sulfides: boosting electrocatalytic performance for hydrogen evolution reaction by cocktail effects Ling Lin, Ziming Ding, Guruprakash Karkera, Thomas Diemant, Dong-Hui Chen, et al. Materials Futures, 2024 This study explores high-entropy sulfides (HESs) as potential electrocatalysts for the hydrogen evolution reaction (HER). Novel Pa-3 and Pnma structured HESs containing Fe, Mn, Ni, Co and Mo, were synthesized via a facile mechanochemical method. Structural and chemical properties were extensively characterized using x-ray diffraction, transmission electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray photoelectron spectroscopy. The electrocatalytic performance of four as-prepared HESs in alkaline electrolyte for HER reveals the remarkable outperformance compared to medium-entropy and conventional sulfides. Particularly, (Fe0.2Mn0.2Ni0.2Co0.2Mo0.2)S2 demonstrated outstanding activities, with minimal overpotentials (187 mV at 10 mA cm–2) and outstanding durability under harsh alkaline conditions (a mere polarization increase ΔE = 17 mV after 14 h via chronopotentiometry). The remarkable catalytic activities can be attributed to synergistic effects resulting from the cocktail effects within the high-entropy disulfide. The introduction of Mo contributes to the formation of a layered structure, which leads to an increased surface area and thus to a superior HER performance compared to other HES and conventional sulfides. This work demonstrates the promising potential of HES and underscores that further development for catalytic applications paves the way for innovative routes to new and more efficient active materials for HER catalysis.
K-Doping Suppresses Oxygen Redox in P2-Na0.67Ni0.11Cu0.22Mn0.67O2 Cathode Materials for Sodium-Ion Batteries Bei Zhou, Deniz Wong, Zhongheng Fu, Hao Guo, Christian Schulz, et al. Small, 2024 In P2‐type layered oxide cathodes, Na site‐regulation strategies are proposed to modulate the Na+ distribution and structural stability. However, their impact on the oxygen redox reactions remains poorly understood. Herein, the incorporation of K+ in the Na layer of Na0.67Ni0.11Cu0.22Mn0.67O2 is successfully applied. The effects of partial substitution of Na+ with K+ on electrochemical properties, structural stability, and oxygen redox reactions have been extensively studied. Improved Na+ diffusion kinetics of the cathode is observed from galvanostatic intermittent titration technique (GITT) and rate performance. The valence states and local structural environment of the transition metals (TMs) are elucidated via operando synchrotron X‐ray absorption spectroscopy (XAS). It is revealed that the TMO2 slabs tend to be strengthened by K‐doping, which efficiently facilitates reversible local structural change. Operando X‐ray diffraction (XRD) further confirms more reversible phase changes during the charge/discharge for the cathode after K‐doping. Density functional theory (DFT) calculations suggest that oxygen redox reaction in Na0.62K0.03Ni0.11Cu0.22Mn0.67O2 cathode has been remarkably suppressed as the nonbonding O 2p states shift down in the energy. This is further corroborated experimentally by resonant inelastic X‐ray scattering (RIXS) spectroscopy, ultimately proving the role of K+ incorporated in the Na layer.
High-Entropy Sulfides as Highly Effective Catalysts for the Oxygen Evolution Reaction Ling Lin, Ziming Ding, Guruprakash Karkera, Thomas Diemant, Mohana V. Kante, et al. Small Structures, 2023 With respect to efficient use of diminishing or harder to reach energy resources, the catalysis of processes that will otherwise require high overpotentials is a very important application in today's world. As a newly developed class of materials, high‐entropy sulfides (HESs) are promising electrocatalysts for a variety of different reactions. In this report, HESs containing five or six transition metals are synthesized in a one‐step mechanochemical process. Seven HESs of Pnma (M:S≈1:1) and three Pa‐3 (M:S = 1:2) structures are investigated as electrocatalysts for the oxygen evolution reaction (OER). The performances and properties of the HESs with different compositions and structures are compared with each other and with commercial IrO2 as reference material, in terms of OER overpotential, Tafel slope, electrochemically active surface area, ionic conductivity, and durability. The structural and chemical properties of these HESs are determined by X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy, and energy‐dispersive X‐ray spectroscopy. Most of the HESs show excellent and promising performance as OER electrocatalysts under alkaline conditions, and outperform the reference OER catalyst IrO2.
Multi-Component PtFeCoNi Core-Shell Nanoparticles on MWCNTs as Promising Bifunctional Catalyst for Oxygen Reduction and Oxygen Evolution Reactions Tobias Braun, Sirshendu Dinda, Guruprakash Karkera, Georgian Melinte, Thomas Diemant, et al. Chemistryselect, 2023 The development of commercially viable fuel cells and metal‐air batteries requires effective and cheap bifunctional catalysts for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Multi‐component Pt−Fe−Co−Ni nanoparticles on multi‐walled carbon nanotubes (MWCNTs) were synthesized by wet chemistry route via NaBH4 reduction of metal salts, followed by sintering at different temperatures. The catalyst demonstrates an excellent ORR activity and a promising OER activity in 0.1 m KOH, with a bi‐functional over‐potential, ΔE of 0.83 V, which is comparable to the values of Pt/C or RuO2. Furthermore, it shows outstanding long‐term stability in ORR and OER, namely diffusion limited current density at a potential of 0.3 V decreased just by 5.5 % after 10000 cycles in ORR. The results of the PFCN@NT300 indicate a significant effect of the substitution of Pt by the transition metal (TM) and the formation of nanoparticles on the catalytic performance, especially in the OER.
Effect of Silicon‐Based Electrolyte Additive on the Solid‐Electrolyte Interphase of Rechargeable Mg Batteries S Guddehalli Chandrappa, G Karkera, S Dinda, M Löw, H Euchner, ... Advanced Science 13 (2), e10456 , 2026 2026 Citations: 1
Cobalt Borate Complex With Tetrahedrally Coordinated Co2+‐Promotes Lithium Superoxide Formation in Li‐O2 Batteries SG Chandrappa, K Forster‐Tonigold, VA Gangadharappa, P Kannan, ... Small, 2502150 , 2025 2025 Citations: 2
Influence of In‐Doping on the Structure and Electrochemical Performance of Compositionally Complex Garnet‐Type Solid Electrolytes A Alsawaf, G Karkera, T Diemant, MV Kante, Y Schneider, L Velasco, ... Small Structures, 2400643 , 2025 2025 Citations: 2
Synthesis, structural analysis, and degradation behavior of Potassium Tin chloride as chloride‐ion batteries conversion electrode material S Panja, Y Miao, J Döhn, J Choi, S Fleischmann, ... Advanced Functional Materials 35 (3), 2413489 , 2025 2025 Citations: 15
Layered High-Entropy Sulfides: Boosting Electrocatalytic Performance for Hydrogen Evolution Reaction by Cocktail Effects L Lin, Z Ding, K Guruprakash, T Diemant, DH Chen, M Fichtner, H Hahn, ... Materials Futures , 2024 2024 Citations: 13
Reactivation of dissolved polysulfides with nitrogen doped graphene decorated carbon cloth as an effective interlayer for magnesium-sulfur battery D Bosubabu, M Sotoudeh, L Wang, Z Li, T Diemant, G Karkera, ... Journal of Energy Storage 99, 113389 , 2024 2024 Citations: 1
K‐Doping Suppresses Oxygen Redox in P2‐Na0. 67Ni0. 11Cu0. 22Mn0. 67O2 Cathode Materials for Sodium‐Ion Batteries B Zhou, D Wong, Z Fu, H Guo, C Schulz, G Karkera, H Hahn, M Bianchini, ... Small, 2402991 , 2024 2024 Citations: 22
High‐entropy sulfides as highly effective catalysts for the oxygen evolution reaction L Lin, Z Ding, G Karkera, T Diemant, MV Kante, D Agrawal, H Hahn, ... Small Structures 4 (9), 2300012 , 2023 2023 Citations: 68
Multi‐Component PtFeCoNi Core‐Shell Nanoparticles on MWCNTs as Promising Bifunctional Catalyst for Oxygen Reduction and Oxygen Evolution Reactions T Braun, S Dinda, G Karkera, G Melinte, T Diemant, C Kübel, M Fichtner, ... ChemistrySelect 8 (29), e202300396 , 2023 2023 Citations: 5
A Structurally Flexible Halide Solid Electrolyte with High Ionic Conductivity and Air Processability (Adv. Energy Mater. 30/2023) MF Guruprakash Karkera, Mervyn Soans, Ayça Akbaş, Raiker Witter, Holger ... Advanced energy materials 13 (30), 2370128 , 2023 2023
A structurally flexible halide solid electrolyte with high ionic conductivity and air processability G Karkera, M Soans, A Akbaş, R Witter, H Euchner, T Diemant, ... Advanced Energy Materials 13 (30), 2300982 , 2023 2023 Citations: 16
Facile Synthesis of Ordered Mesoporous Orthorhombic Niobium Oxide (T-Nb 2 O 5 ) for High-Rate Li-Ion Storage with Long Cycling Stability E Umeshbabu, D Velpula, G Karkera, M Satyanarayana, V Pasala, ... Batteries 9 (7), 357 , 2023 2023 Citations: 11
An air processable solid ion conductor for secondary all solid-state metal batteries GKM Fichtner EP Patent App. EP23156313.1 , 2023 2023
KNi 0.8 Co 0.2 F 3 as an Efficient Electrocatalyst for Nonaqueous Li–O 2 Batteries S Guddehalli Chandrappa, G Karkera, V A. Gangadharappa, D Chen, ... ACS Applied Energy Materials 5 (12), 14680-14686 , 2022 2022 Citations: 10
Long-Cycle-Life Calcium Battery with a High-Capacity Conversion Cathode Enabled by a Ca 2+ /Li + Hybrid Electrolyte Z Meng, A Reupert, Y Tang, Z Li, G Karkera, L Wang, A Roy, T Diemant, ... ACS Applied Materials & Interfaces 14 (49), 54616-54622 , 2022 2022 Citations: 27
Synthesis of Perovskite-Type High-Entropy Oxides as Potential Candidates for Oxygen Evolution S Schweidler, Y Tang, L Lin, G Karkera, A Alsawaf, L Bernadet, B Breitung, ... Frontiers in Energy Research, 1881 , 2022 2022 Citations: 34
P2-Type Layered High-Entropy Oxides as Sodium-Ion Cathode Materials BBQW Junbo Wang, Sören Lukas Dreyer, Kai Wang, Ziming Ding, Thomas Diemant ... Materials Futures , 2022 2022 Citations: 105
Tungsten oxytetrachloride as a positive electrode for chloride‐ion batteries G Karkera, M Soans, B Dasari, U Ediga, MA Cambaz, Z Meng, T Diemant, ... Energy Technology 10 (8), 2200193 , 2022 2022 Citations: 13
High‐Entropy Sulfides as Electrode Materials for Li‐Ion Batteries (Adv. Energy Mater. 8/2022). L Lin, K Wang, A Sarkar, C Njel, G Karkera, Q Wang, R Azmi, M Fichtner, ... Advanced Energy Materials 12 (8) , 2022 2022 Citations: 2
High‐entropy sulfides as electrode materials for Li‐ion batteries L Lin, K Wang, A Sarkar, C Njel, G Karkera, Q Wang, R Azmi, M Fichtner, ... Advanced energy materials 12 (8), 2103090 , 2022 2022 Citations: 252
MOST CITED SCHOLAR PUBLICATIONS
High‐entropy sulfides as electrode materials for Li‐ion batteries L Lin, K Wang, A Sarkar, C Njel, G Karkera, Q Wang, R Azmi, M Fichtner, ... Advanced energy materials 12 (8), 2103090 , 2022 2022 Citations: 252
Li 4 NiTeO 6 as a positive electrode for Li-ion batteries M Sathiya, K Ramesha, K Guruprakash, G Tarascon, J-M, Rousse, ... Chemical Communications 49 (97), 11376-11378 , 2013 2013 Citations: 209
Recent developments and future perspectives of anionic batteries G Karkera, MA Reddy, M Fichtner Journal of Power Sources 481, 228877 , 2020 2020 Citations: 130
P2-Type Layered High-Entropy Oxides as Sodium-Ion Cathode Materials BBQW Junbo Wang, Sören Lukas Dreyer, Kai Wang, Ziming Ding, Thomas Diemant ... Materials Futures , 2022 2022 Citations: 105
Electrochemical and Compositional Characterization of Solid Interphase Layers in an Interface-Modified Solid-State Li-Sulfur Battery MF Syed Atif Pervez, Bhaghavathi P. Vinayan, Musa Ali Cambaz, Georgian ... J. Mater. Chem. A, 2020, , 2020 2020 Citations: 69
High‐entropy sulfides as highly effective catalysts for the oxygen evolution reaction L Lin, Z Ding, G Karkera, T Diemant, MV Kante, D Agrawal, H Hahn, ... Small Structures 4 (9), 2300012 , 2023 2023 Citations: 68
Influence of Ruthenium Substitution in LaCoO3 towards Bi-functional Electrocatalytic activity for Rechargeable Zn-Air Battery RACASP Shivaraju C Guddehalli, Prabu Moni, Dehong Chen, Guruprakash Karkera ... J. Mater. Chem. A , 2020 2020 Citations: 65
Design and Development of Efficient Bifunctional Catalysts by Tuning the Electronic Properties of Cobalt–Manganese Tungstate for Oxygen Reduction and Evolution Reactions G Karkera, AS Tanmay Sarkar, Mridula Dixit Bharadwaj, Prakash ChemCatChem 9 (19), 3681–3690 , 2017 2017 Citations: 56
Facile approach to prepare multiple heteroatom-doped carbon material from bagasse and its applications toward lithium-ion and lithium–sulfur batteries D Bosubabu, R Sampathkumar, G Karkera, K Ramesha Energy & Fuels 35 (9), 8286-8294 , 2021 2021 Citations: 47
Synthesis of Perovskite-Type High-Entropy Oxides as Potential Candidates for Oxygen Evolution S Schweidler, Y Tang, L Lin, G Karkera, A Alsawaf, L Bernadet, B Breitung, ... Frontiers in Energy Research, 1881 , 2022 2022 Citations: 34
An Inorganic Electrolyte Li–O 2 Battery with High Rate and Improved Performance G Karkera, AS Prakash ACS Applied Energy Materials 1 (3), 1381-1388 , 2018 2018 Citations: 33
Long-Cycle-Life Calcium Battery with a High-Capacity Conversion Cathode Enabled by a Ca 2+ /Li + Hybrid Electrolyte Z Meng, A Reupert, Y Tang, Z Li, G Karkera, L Wang, A Roy, T Diemant, ... ACS Applied Materials & Interfaces 14 (49), 54616-54622 , 2022 2022 Citations: 27
K‐Doping Suppresses Oxygen Redox in P2‐Na0. 67Ni0. 11Cu0. 22Mn0. 67O2 Cathode Materials for Sodium‐Ion Batteries B Zhou, D Wong, Z Fu, H Guo, C Schulz, G Karkera, H Hahn, M Bianchini, ... Small, 2402991 , 2024 2024 Citations: 22
Decoupling the Cumulative Contributions of Capacity Fade in Ethereal-Based Li–O 2 Batteries G Karkera, AS Prakash ACS applied materials & interfaces 11 (31), 27870-27881 , 2019 2019 Citations: 22
Ultrasonochemically-induced MnCo 2 O 4 nanospheres synergized with graphene sheet as a non-precious bi-functional cathode catalyst for rechargeable zinc–air battery SG Chandrappa, P Moni, G Karkera, AS Prakash Nanoscale Advances 1 (6), 2392-2399 , 2019 2019 Citations: 22
Viable Synthesis of Porous MnCo 2 O 4 /Graphene Composite by Sonochemical Grafting: A High‐Rate‐Capable Oxygen Cathode for Li–O 2 Batteries G Karkera, SG Chandrappa, AS Prakash Chemistry–A European Journal 24 (65), 17303-17310 , 2018 2018 Citations: 21
Fluoride Perovskite (KNi x Co 1– x F 3 ) Oxygen-Evolution Electrocatalyst with Highly Polarized Electronic Configuration S Guddehalli Chandrappa, P Moni, D Chen, G Karkera, KR Prakasha, ... ACS Applied Energy Materials 4 (12), 13425-13430 , 2021 2021 Citations: 20
A structurally flexible halide solid electrolyte with high ionic conductivity and air processability G Karkera, M Soans, A Akbaş, R Witter, H Euchner, T Diemant, ... Advanced Energy Materials 13 (30), 2300982 , 2023 2023 Citations: 16
Synthesis, structural analysis, and degradation behavior of Potassium Tin chloride as chloride‐ion batteries conversion electrode material S Panja, Y Miao, J Döhn, J Choi, S Fleischmann, ... Advanced Functional Materials 35 (3), 2413489 , 2025 2025 Citations: 15
Hierarchical α-MnO 2 nanowires as an efficient anode material for rechargeable lithium-ion batteries E Umeshbabu, M Satyanarayana, G Karkera, A Pullamsetty, P Justin Materials Advances 3 (3), 1642-1651 , 2022 2022 Citations: 14
