Lithium LiNiO

Julien, C., Letranchant, C., Lemal, M., Ziolkiewicz, S., Castro-Garcia, S., Layered LiNio 5Coo 502 compounds synthesized by a glycine-assisted combustion method for lithium batteries, J. Mater. Sci. 37,2367-2375 (2002). 

Like all the phosphates investigated as cosolvents, TBP and TPP showed higher anodic stability, as confirmed by their cycling in lithium ion cells based on a LiNio.8Coo.2O2 cathode up to 4.2 V, and separate cyclic voltammetry tests also showed that they would not decompose anodically below 5.0 V on an inert working electrode. Little capacity fading was detected during the extended tests of TPP or TBP in full lithium ion cells up to 150 cycles. 

The high cost and toxicity of cobalt compounds has prompted a search for alternative materials that intercalate lithium ions. Examples of these are LiMn204 [iv], LiCoo.2Nio.8O2. LiNio.5Mni.504 [v], LiNio.5Mno.5O2 [vi], LiFeP04 [vii], Lix VO [viii], and LixMrVOz (M = Ca, Cu) [ix], etc. 

Ohzuku, T. Makimura, Y. Layered lithium insertion material of LiNio.5Mno.5O2 a possible alterative to LiCo02 for advanced lithium-ion batteries. Chem. Lett. 2001, 30, 744. 

Another interesting application of the lithium-ion battery concept has been applied to the Sn02/LiNio gCog 2O2 electrodic couple [92]. Convertible oxides, and tin oxide in particular, first proposed as alternative anode materials by the Japanese Fuji Photo Film Company [93, 94], are presently the object of considerable attention in the lithium-ion battery community [95-98]. When negatively polarised in a lithium cell, tin oxide first undergoes an irreversible reaction shown in Equation 7.10. 

Two types of solid solution are known in the cathode material of the lithium-ion battery. One type is that two end members are electroactive, such as LiCo Ni 02, which is a solid solution composed of LiCo02 LiNiO. The other type has one electroactive material in two end members, such as LiNi02 Li2Mn03 solid solution. LiCoO, LiNiQ Mn O, LiCrO, LiMnO and LiFeO are electroactive end members on the other hand, Li MnOg, Li2Ti03 and LiAlO are electrochemically... 

The layered LiNiO is expected to be a cathode material for the next generation of lithium-ion battery. Figure 16.1 shows the relationship between discharge capacity and voltage for cathode materials for the lithium-ion battery. It means that LiNiO has a higher capacity compared with other materials. In spite of this, LiNiO compounds have not been used in commercially available lithium-ion batteries. It is thought that LiNiOj presents the following potential problems ... 

Toda Kogyo Corporation is promoting the development for each cathode material for lithium-ion batteries depending on their use for example, LiCoO for notebook personal computers and cellular phones LiMn O for hybrid electric vehicles (HEV) and LiNiO for high-capacity batteries. Special efforts are being made in the improvement of the above problems, i.e., cycle characteristics and thermal stability, for LiNiOj, so that this compound can be included in the market trend of lithium ion batteries. This chapter presents the results of the process development to improve the above-mentioned problem. 

In addition, the ratio of Ni + by redox titration was examined. The ratio of the wet process and the dry process were 99% and 95%, respectively. This can be attributed to cation disorder of Ni + and Li+. These results indicate that the wet mixing process can uniformly mix the precursor and the lithium salt and it is effective in structural stabilization for LiNiO. ... 

LiNiO with high-packing density can be produced by using high-density precursor, and it should effectively improve the capacity of the lithium-ion battery. 

These results indicate that the problems mentioned in the first section of this chapter can be resolved, and LiNiO can be considered to be a cathode material of lithium-ion batteries. 

Another important, now commercially available, family of cathode material is Li[NiCo]02 compounds. The most important one is the Al-doped LiNio,8Coo.202 compound. These compounds also develop very rich surface chemistry. For example, the formation of surface films formed on LiNio,85Coo.i502 cathodes in lithium-ion cells was characterized using soft X-ray absorption spectroscopy (XAS) [60]. Surface LiF formation was clearly detected by surface studies of these electrodes. The surface reactivity increases and is accelerated as the temperature is higher [61]. 

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