Synthesis of novel nanostructured composite cathode materials for lithium-ion batteries using mechanical activation

Abstract

on lithium-ion batteries (LIBs). One of the promising approaches to the optimization of their properties is in the development of new blended composite electrode materials consisting of two (or more) active components in order to use the advantages of the both of them [1]. Due to a unique combination of properties, the mixed materials show some advantages over the individual components. This includes the longer lifetime, the decreased capacity fading upon the cycling, lower price, the improved thermal stability, more acceptable profiles of charge-discharge curves and operating voltage, etc. For instance, the cathode materials with a layered structure (LiCoO 2 ) have a high Coulomb capacity and good electrochemical properties, but are expensive and thermally unstable. On the contrary, cathode materials with a spinel structure (LiMn 2 O 4 ) are characterized by high thermal stability and good cycleability, but show lower capacity. Mixing these two cathode materials minimizes their disadvantages, and the composite material is characterized by high energy or power, along with higher stability and lower price.In the present work, we formulate the new approaches to the development of novel composite electrode materials for LIB, using the mechanical activation method (MA). MA with high-energy mechanoactivators is a modern energy-and eco-efficient method of fine grinding, mixing, and activation of solid reagents and is widely used to prepare different functional materials [2,3]. As an example, we report the results of studying the synthesis, structure, morphology, and electrochemical properties of the composite cathode materials prepared by different procedures: 1) joint MA of two individual cathode materials (the LiCoO 2 /LiMn 2 O 4 composites); 2) direct mechanochemically assisted solid state synthesis starting from a multicomponent mixture of reagents (LiFePO 4 /Li 3 V 2 (PO 4 ) 3 composites); 3) synthesis via heatinduced partial decomposition of a single-phase nanosized cathode material, prepared by MA,

Synthesis and electrochemical properties of composite cathode materials

“…3. The predominance of the solid-phase electrodes we developed over the known foreign [3] and domestic [6] analogs in specifi c capacity and stability is due to a number of factors. For example, the role of the electrically conducting additive in electrode nos.…”

“…3 and 4 is played by acetylene black, which is not the optimal material, in contrast to CNTs [7]. At the [2], (3) LiFePO 4 /Li 3 V 2 (PO 4 ) 3 [6], and (4) LiFePO 4 [3].…”

“…One of promising venues of research is development of mixed formulations of electrode materials, which are composed of two (or more) active components in order to enjoy the advantages of both of these [6]. Owing to the unique combination of properties, mixed electrodes have advantages over the individual components.…”

“…These are the longer service life, lower loss of capacity in cycling, lower cost, better thermal stability, and acceptable profi les of charge-discharge curves and values of the working potential, etc. For example, the authors of [6] synthesized LiFePO 4 /Li 3 V 2 (PO 4 ) 3 composites, with mechanical activation via joint carbothermic reduction of Fe 2 O 3 and V 2 O 5 in a mixture with Li 2 CO 3 and (NH 4 ) 2 HPO 4 . It was demonstrated that composite electrodes exhibit a more stable cycling in a wide range of current densities, compared with the individual components.…”

Композитні Електроліти На Основі Полівініліденфториду Для Літій-Іонних Акумуляторів

“…The advantages of the CPE are the improved ionic conductivity, mechanical properties, greater chemical stability at the electrolyte/electrode interface and possibility to obtain composites in the form of thin, durable and elastic films [1][2][3][4]. Polymer electrolytes, where lithium salts in a polymer matrix, are currently gaining attention [5][6][7][8].…”