To be used as a lithium-ion battery material, it is, however, not enough that the material has a high electronic conductivity and a high surface area. A good negative electrode material also needs to undergo a reduction during the lithiation step and an oxidation during the subsequent delithiation step.
This mini-review discusses the recent trends in electrode materials for Li-ion batteries. Elemental doping and coatings have modified many of the commonly used electrode materials, which are used either as anode or cathode materials. This has led to the high diffusivity of Li ions, ionic mobility and conductivity apart from specific capacity.
The limitations in potential for the electroactive material of the negative electrode are less important than in the past thanks to the advent of 5 V electrode materials for the cathode in lithium-cell batteries. However, to maintain cell voltage, a deep study of new electrolyte–solvent combinations is required.
It should be noted that the potential applicability of this anode material in commercial lithium-ion batteries requires a careful selection of the cathode material with sufficiently high voltage, e.g. by using 5 V cathodes LiNi 0.5 Mn 1.5 O 4 as positive electrode.
2. Recent trends and prospects of anode materials for Li-ion batteries The high capacity (3860 mA h g −1 or 2061 mA h cm −3) and lower potential of reduction of −3.04 V vs primary reference electrode (standard hydrogen electrode: SHE) make the anode metal Li as significant compared to other metals , .
Two lines of research can be distinguished: (i) improvement of LiCoO 2 and carbon-based materials, and (ii) replacement of the electrode materials by others with different composition and structure. Concerning the positive electrode, the replacement of lithium cobaltate has been shown to be a difficult task.