Compound 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). 

XPS studies have been made on a number of compositions of these transition-metal oxides, and all indicate predominantly divalent nickel. Thus, for the 442 compound the Co spectrum is clearly Co +, and the Mn spectrum can be assigned to 80% Mn" + with 20% Mn +. The Ni spectrum is characterized by an intense and complicated satellite structure and consistent with 80% NP+ and 20 NP+. Studies on LiNio.33Mno.33Coo.3302, LiNio.5Mno.502, and... 

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. 

It can be understood that the temperature of the exothermic peak with oxygen evolution increased from 200°C of LiNiO to 310°C of LiNi gCo j Al due to the decrease in the nickel content and the aluminum doping. The thermal stability of this compound has been considerably improved. The oxygen evolution was not observed below 300°C. On the whole, the thermal stabihty of this is more excellent than that of LiCoO and comparable to that of spinel LiMn O. hi addition, the SEM image of this material is shown in Fig. 2.23. It would be possible to control the powder characteristics the same as the co-precipitation method. It is clear from Table 2.5 that this material has a larger capacity than that of the cobalt-based cathode. This cathode delivers more than 180 mAh/g for 4.3 V charge, as shown in Fig. 2.24. 

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. 

Generally, LiNiO is prepared using nickel hydroxide particles as a precursor, its high-packing density being one important characteristic of this compound. Toda Kogyo Corporation succeeded in the original development of a synthetic method to... 

Lithiated transition metal oxides These compounds can be classified via their structure layered compounds (e.g., LiCo02, LilMnNiCoJOa) and spinel (e.g., LiMn204, LiNio sMni 5O4) [3]. 

It should be noted that the surface activity and possible formation of surface films depend strongly on the composition of the LiMOa compounds. The order of surface reactivity is LiNi02>LiCo02>LiMn204 [58], Matsui et al. [59] reported on the possibility to have periodic surface film formation on LiMn204 and LiNio,5Mni 5O4 electrodes, driven by the periodic redox activity of the transition metal upon cycling. 

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]. 

Ngala JK, Chernova NA, Ma M, Mamak M, Zavalij PY, Whittingham MS (2004) The synthesis, characterization and electrochemical behavior of the layered LiNio.4Mno.4Coo.2O2 compound. J Mater Chem 14 214—220... 

Cathode Lithium compound (e.g. LiCoC2r LiFeP04, LiMn204, LiNio.sCoo.15Alo.05O2)... 

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