Mariya Kalapsazova

Bulgarian Academy of Sciences | BAS · Institute of General and Inorganic Chemistry

To make supercapattery devices feasible, there is an urgent need to find electrode materials that exhibit a hybrid mechanism of energy storage. Herein, we provide a first report on the capability of lithium manganese sulfates to be used as supercapattery materials at elevated temperatures. Two compositions are studied: monoclinic Li2Mn(SO4)2 and or...

The bottleneck in the implementation of hybrid lithium-sodium-ion batteries is the lack of anode materials with a desired rate capability. Herein, we provide an in-depth examination of the Li-storage performance of sodium titanate nanowires as negative electrodes in hybrid Li,Na-ion batteries. Titanate nanowires were prepared by a simple and reprod...

Layered sodium transition metal oxides belong to electrode materials for sodium-ion batteries that combine, in a better way, high performance with environmental requirements. However, their cycling stability is still far from desirable. Herein, we demonstrate a rational approach to control the cycling stability of sodium-deficient nickel manganese...

To outline the role of dual-ion intercalation chemistry to reach sustainable energy storage, the present review aims to compare two types of batteries: widely accepted dual-ion batteries based on cationic and anionic co-intercalation versus newly emerged hybrid metal-ion batteries using the co-intercalation of cations only. Among different charge c...

Sodium-deficient nickel-manganese oxides with three-layered stacking exhibit the unique property of dual nickel-oxygen redox activity, which allows them to achieve enormous specific capacity. The challenge is how to stabilize the oxygen redox activity during cycling. This study demonstrates that oxygen redox activity of P3-Na2/3Ni1/2Mn1/2O2 during...

Double sulfate salts of sodium and manganese, Na2Mn2(SO4)3, with an alluaudite-type of structure has been shown to intercalate Li⁺ ions reversibly, but the mechanism is still unclear. This study aims to examine the structure transformation of the alluaudite sodium manganese sulfate Na2Mn2(SO4)3 after Li⁺ intercalation by means of ex-situ transmissi...

Hybrid metal ion batteries are perceived as competitive alternatives to lithium ion batteries since they provide better balance between energy/power density, battery cost and environmental requirements. However, their cycling stability and high-temperature storage performance are still far from the desired. Herein, we firstly examine the temperatur...

The integration of sodium ion batteries into large‐scale energy storage systems will become feasible in the case when their performance becomes less sensitive towards the ambient temperature. Herein, we demonstrate firstly the elaboration of the oxide‐based electrode material with optimized layered structure and composition that is designed to work...

A simple precursor method was adopted for the preparation of Mg-substituted oxides, Na2/3Ni1/2-xMgxMn1/2O2 (0 ≤ x ≤ 1/6). The insertion of Mg2+ ions causes a stabilization of the three layer stacking (P3-type structure, space group R3m). The refined lattice parameters seems unchanged after Mg-substitution. By increasing the Mg content, the particle...

Hybrid Li-Na ion batteries (HLSIBs) become attractive since they combine the high energy density of lithium ion batteries with the safety and low cost of sodium ion batteries. However, the performance of HLSIBs is still far from the desired. The present study aims to probe the function of electrodes and electrolyte in model half and full hybrid Li-...

The growing demand for effective energy storage systems requires new generations of batteries that have not only high specific capacity and power density, but also high safety, long cycle life and low price. In the last few years, the sodium ion batteries have been advanced as an alternative to the lithium ion technology because of the low-cost and...

The knowledge on the formation of mixed transition metal layers on lithium and sodium transition metal oxides, Li/Na(Co,Ni,Mn,)O2, determines the ability to control their electrochemical properties as electrode materials in alkaline ion batteries. Taking into account this, herein we combine the EPR and 23Na MAS NMR spectroscopic techniques in order...

The aim of the study is to investigate the electrochemical performance of dual-metal-ion full cell of the type Li4Ti5O12|LiPF6(EC:DMC)|Na0.67Ni0.5Mn0.5O2

Sodium-deficient nickel-manganese oxides with a layered type of structure are, nowadays, of great interest as electrode materials for both lithium- and sodium-ion batteries, since they are able to intercalate lithium and sodium ions reversibly within a broad concentration range. Herein we report new data on the effects of the particle sizes and of...

The aim is to study the structural changes during reversible electrochemical intercalation of lithium and sodium into layered NaxNi0.5Mn0.5O2 oxides with P3- type structure via ex-situ XRD and TEM analyses.

The study aims to explore the effect of the electrolyte composition (LiPF6 or LiBF4) and the start mode of charging on the electrochemical performance of Na0.67Ni0.5Mn0.5O2 used as a cathode in model lithium-ion cell.

Sodium-deficient nickel–manganese oxides exhibit a layered structure, which is flexible enough to acquire different layer stacking. The effect of layer stacking on the intercalation properties of P3-NaxNi0.5Mn0.5O2 (x=0.50, 0.67) and P2-Na2/3Ni1/3Mn2/3O2, for use as cathodes in sodium- and lithium-ion batteries, is examined. For P3-Na0.67Ni0.5Mn0.5...

Sodium deficient nickel-manganese oxides NaxNi0.5Mn0.5O2 with a layered structure are of interest since they are able to participate in reactions of intercalation of Li+ and exchange of Na+ with Li+. Taking into account the intercalation properties of these oxides, we provide new data on the direct use of NaxNi0.5Mn0.5O2 as low-cost electrode mater...

New data on the structure and reversible lithium intercalation properties of sodium-deficient nickel–manganese oxides are provided. Novel properties of oxides determine their potential for direct use as cathode materials in lithium-ion batteries. The studies are focused on Nax Ni0.5Mn0.5O2 with x = 2/3. Between 500 and 700 °C, new layered oxides Na...