Charge-discharge cycle characteristics

Figure 10. Charge-discharge cycle characteristics of an Ni-Cd battery (cell type 1200SC).

Figure 10 shows the charge-discharge cycle characteristics. As shown in this fig-... 

Figure 16 shows the charge-discharge cycle characteristics of alloys in which part of the nickel component was replaced with cobalt. Misch metal (Mm), which is a mixture of rare earth elements such as lanthanum, cerium, praseodymium, and neodymium, was used in place of lanthanum. It was found that the partial replacement of nickel with cobalt and the substi-... 

Figure 3. Charge-discharge cycling characteristics of an Li/LiMn, yCo0, 04 coin-type cell (thickness 2 mm, diameter 23 mm). Charge 4.3 V, 1 niAcm-2 discharge 3.3 V, 3 mAcm 2 I molL-1 LiPF6 - EC/DMC (jr I00-x).

Charge/discharge cycle characteristics for a cell operating at room temperature are shown in Fig. 6.21. The high cell voltage under load (> 1.5 V even at a rate of 2 C) is noteworthy. 

As mentioned above, lithium carbonate is used as the raw material for lithium, and cobalt oxide is mainly used as the raw material for cobalt. However, there are many kinds of lithium carbonates and cobalt oxides, which have various powder properties. The characteristics of the synthesized LiCoO is significantly different depending on the mean particle size, the liability to flocculate, and the impurities as shown in the example below. The examples are shown in Fig. 15.7. It can be understood that the two kinds of LiCoO, which have similar physical properties, exhibit different charge-discharge cycle characteristics. 

Figure 2.10 shows the charge-discharge cycle characteristics. As shown in this figure, nickel-cadmium batteries exhibit excellent cycle characteristics and no noticeable decline is observed after 1000 charge-discharge cycles. 

Figure 2.16 shows the charge-discharge cycle characteristics of alloys in which part of the nickel component was replaced with cobalt. Misch metal (Mm), which is a mixture of rare earth elements such as lanthanum, cerium, praseodymium, and neodymium, was used in place of lanthanum. It was found that the partial replacement of nickel with cobalt and the substitution of the lanthanum content with Mm was very useful in improving the charge-discharge cycle life. However, such alloys have insufficient capacity, as shown in Figure 2.17 [18]. From study of the effect that their compositions had on the charge-discharge capacity, it was concluded that the best alloy elements were Mm(Ni-Co-Al-Mn)This alloy led to the commercialization of sealed nickel-M H batteries. All the battery manufacturers who use a rare earth-nickel-type alloy for the negative electrode material employ similar alloys with slightly different compositions.

Figure 2.16 Charge-discharge cycle characteristics of various iVIH alloy electrodes.

These techniques are useful for improving cell characteristics such as cell capacity and charge-discharge cycle life. 

---