Fyodor Malchik

• PhD
• Senior Researcher at Al-Farabi Kazakh National University

This study investigates the electrochemical characteristics of nanostructured LaNi5 intermetallic synthesized via the sol-gel method for application as an anode material in nickel-metal hydride (Ni-MH) batteries. A comparison with a commercial counterpart produced by fusion synthesis with mechanical grinding revealed that the nanostructured materia...

The layered material MXene (Ti3C2Tx) has a high specific surface area and variable surface functional groups, which creates the possibility of its application in various directions. One of them is the water electrolysis to produce ‘green’ hydrogen. However, in its pure form, MXene has low catalytic activity for this process, so it is modified by va...

Choline bromide (ChBr) has been less explored as an electrolyte material. This work demonstrates the promising potential of ChBr as a novel aqueous electrolyte for hybrid supercapacitors. At its optimized concentration of 3.5 M, ChBr solution exhibits a maximum conductivity of 79.56 mS cm⁻¹ at room temperature, along with a viscosity of 3.15 mPas a...

Hydrogen, widely recognized as an efficient and clean energy carrier, holds significant promise for transforming future energy systems. Despite advances in hydrogen production and cost reduction, challenges in hydrogen storage continue to impede its widespread adoption. Traditional storage methods, such as high-pressure tanks and liquid hydrogen, h...

With the increasing demand for energy-efficient technologies, there is a growing focus on developing new materials for supercapacitors and other energy devices. MXene Ti3C2Tx is known for its unique electrochemical properties and has garnered significant interest in such applications. However, the high cost of synthesizing MXene limits its commerci...

Supercapacitors are widely acknowledged as crucial devices for storing and converting electrical energy, alongside batteries and fuel cells. Their ability to rapidly charge and discharge, typically within seconds or even milliseconds, makes them ideal for high-power applications. This feature provides significant advantages for electric vehicles, s...

Rising production and consumption, and the high cost of lithium salts increased the price of lithium-ion batteries. Sodium-ion batteries are a promising replacement as safer and cheaper. However, the cathode materials for these batteries have low conductivity, which critically reduces their capacity. Modification with conductive additives is one wa...

The development of integrated micro‐power sources is mainly driven by innovative investigations in materials chemistry, battery designs, and microfabrication processes. Here, a new technique is described for the development of coaxial wire‐shaped Li‐ion batteries by successfully adopting the unidirectional helical winding method starting from a twi...

Zinc metal, with its high theoretical capacity and low cost, stands out as a promising anode material for affordable high energy-density storage technologies in rechargeable batteries. However, obtaining a high...

Aqueous electrolytes offer enhanced safety and environmental friendliness for next-generation energy storage systems, but their application is limited by a narrow electrochemical stability window. This study provides a comprehensive analysis...

The exploration of cathode and anode materials that enable reversible storage of mono and multivalent cations has driven extensive research on organic compounds. In this regard, polyimide (PI)‐based electrodes have emerged as a promising avenue for the development of post‐lithium energy storage systems. This review article provides a comprehensive...

The exploration of cathode and anode materials that enable reversible storage of mono and multivalent cations has driven extensive research on organic compounds. In this regard, polyimide (PI)‐based electrodes have emerged as a promising avenue for the development of post‐lithium energy storage systems. This review article provides a comprehensive...

The use of Ti3C2Tx (MXene) electrodes for energy storage applications is gaining momentum. Considering the low flammability, high safety, and low cost of neutral aqueous electrolyte solutions, significant efforts have been devoted to the utilization of MXenes in this environment. However, despite the high stability and the excellent rate capability...

The membrane/separator is an important part of electrochemical energy storage devices such as supercapacitors and batteries. However, the transport processes that limit the rate capability of the charge/discharge are more pronounced for supercapacitors, which can be charged in seconds, unlike batteries; therefore, a more detailed selection of the m...

The discovery of the Ti3C2Tx compounds (MXenes) a decade ago opened new research directions and valuable opportunities for high‐rate energy storage applications. The unique ability of the MXenes to host various mono‐ and multivalent cations and their high stability in different electrolyte environments including aqueous, organic, and ionic liquid s...

The emerging interest in aqueous rechargeable batteries has led to significant progress in the development of next-generation electrolytes and electrode materials enabling reversible and stable insertion of various multivalent ions into the electrode's bulk. Yet, despite its abundance, high salt solubility, and small ionic radius, the use of mangan...

The optimal performance of organic electrodes for aqueous batteries requires their full compatibility with selected electrolyte solutions. Electrode materials having 1-3-dimensional structures of variable rigidity possess a confined space in their structure filled with water and electrolyte solutions. Depending on the rigidity and confined space ge...

To determine the impact of the electrode composite parameters of metal-ion intercalation into host materials with poor conductivity, the processes were simulated with varying possible values of parameters. A physical model is proposed for the intercalation into an active material particle that has point contacts with an electronic conductor, consid...

The need for low-cost, high-safety batteries for large-scale energy storage applications has sparked a surge in research of rechargeable aqueous batteries. While most research efforts are focused on the development of electrolyte formulations and electrode materials, it appears that the current collector impact on the battery performance is frequen...

The lack of stable electrode materials for water-based electrolytes due to the intercalation and conversion reaction mechanisms encourage scientists to design new or renovate existing materials with better cyclability, capacity, and cost-effectiveness. Ag4[Fe(CN)6] is a material belonging to the Prussian blue family that can be used, as its other f...

Increasing surface area between electrodes and electrolytes drastically has proven to improve electrochemical performances of microbatteries. 3D surface enhancement owing to the design of micropillar electrodes has permitted to fulfill this need while maintaining the same footprint area. Lithium nickel manganese oxide (cathode) and Lithium titanate...

Extensive efforts are currently underway to develop safe and cost-effective electrolytes for large-scale energy storage. In this regard, water-based electrolytes may be an attractive option, but their narrow electrochemical stability window hinders their realization. Although highly concentrated fluorinated electrolytes have been shown to be highly...

Identifying and understanding charge storage mechanisms is important for advancing energy storage. Well-separated peaks in cyclic voltammograms (CVs) are considered key indicators of diffusion-controlled electrochemical processes with distinct Faradaic charge transfer. Herein, we report on an electrochemical system with separated CV peaks, accompan...

The article deals with the problem of electrochemical conversion of low-conductive materials considering an example of eldfellite-structured NaFe(SO4)2. The applying process of electronically-conducting material on NaFe(SO4)2 surface by means of milling providing multiple contacts with the conductive phase and thus delivering electrons to the activ...

Identifying and understanding charge storage mechanisms is important for advancing energy storage, especially when new materials and electrolytes are explored. Well-separated peaks in cyclic voltammograms (CVs) are considered key indicators of diffusion-controlled electrochemical processes with distinct Faradic charge transfer. Herein, we report on...

Identifying and understanding charge storage mechanisms is important for advancing energy storage, especially when new materials and electrolytes are explored. Well-separated peaks in cyclic voltammograms (CVs) are considered key indicators of diffusion-controlled electrochemical processes with distinct Faradic charge transfer. Herein, we report on...

The purpose of this paper is to suggest frontier inter‐disciplinary research directions that can be considered as important horizons of modern electrochemistry in the field of energy storage and conversion. We selected several topics that call for advancements in solid‐state, interfacial, analytical and energy‐related electrochemical science. A dra...

The need for improved batteries and supercapacitors, which are not based on lithium compounds, promotes significant research efforts to find suitable alternative systems based on various mono and multivalent cations capable of delivering high energy and power density with good long-term stability. The progress in aqueous Zn-ion batteries and superc...

The newly emerging demand for ‘beyond-lithium’ electrochemical energy storage systems necessitates the development of alternative options in providing sustainable cost-effective storage capabilities. In pursuit of discovering such a solution, the intercalation of bisulfate anions into graphite in 17 M H2SO4 solutions has been revaluated. Although t...

Nanoporous layers are widely spread in nature and among artificial devices. However, complex characterization of extensively nanoporous thin films showing porosity-dependent softening lacks consistency and reliability when using different analytical techniques. We introduce herein, a facile and precise method of such complex characterization by mul...

Development of high power devices with improved energy density is a highly desired target for advanced energy storage applications. Herein we propose a new strategy of triply-hybridized supercapacitive energy storage device composed of hybrid battery-supercapacitor negative electrode [Mo6S8 (Chevrel-phase)/Ti3C2 (MXene)] coupled with positive nanop...

The kinetics of LiFePO4 oxidation by hydrogen peroxide in aqueous alkaline medium is studied with the use of potentiometric determination of lithium concentration in solution during delithiation. It is demonstrated that the lithium transfer through the reaction-product layer is controlled by diffusion. The activation energy and the diffusion coeffi...

The disposal of LiFePO4 (LFP) cathode material through oxidation in an air atmosphere is explained by its high chemical activity and high surface area (especially for nanoparticles). In this article, new methods for the determination of the degree of iron oxidation in LFP (oxidation degree) are taken into consideration, specifically those which do...

In the last two decades, a huge attention has been paid to lithium-ion batteries with cathode material based on lithium iron phosphate (LiFePO4). This material is quite environmentally friendly and thermally stable in a fully discharged state. One of the main problems associated with the massive use of the cathode material, is to overcome the limit...