Cycled performance

One criterion for the anode material is that the chemical potential of lithium in the anode host should be close to that of lithium metal. Carbonaceous materials are therefore good candidates for replacing metallic lithium because of their low cost, low potential versus lithium, and wonderful cycling performance. Practical cells with LiCoOj and carbon electrodes are now commercially available. Finding the best carbon for the anode material in the lithium-ion battery remains an active research topic. 

Figure 39. Cycling performance of various manganese oxide electrodes.

An Li-Al Alloy was investigated for use as a negative electrode material for lithium secondary batteries. Figure 41 shows the cycle performance of a Li-Al electrode at 6% depth of discharge (DOD). The Li-Al alloy was prepared by an electrochemical method. The life of this electrode was only 250 cycles, and the Li-Al alloy was not adequate as a negative material for a practical lithium battery. 

Figure 41. Cycling performance of several Li-Al alloy electrodes (discharge end 6% of total Li in Li-Al alloy current density 1.1 mA cm 2 ).

Several metal additives were investigated to improve this nonuniform reaction. Figure 41 shows the cycle performance of several Li-Al alloy electrodes. It was found that Li-Al-Mn and Li-Al-Cr alloys had better rechargeability than Li-Al alloy in the Li-Al-Mn alloy, particularly no de-... 

Figure 46. Cycling performance of the Li-Al-CDMO cell (ML2430). The number of 100% charge-discharge cycles is calculated until the capacity drops to 100% of the nominal value (end voltage 2.0 V). The number of 5%, 20% and 60% charge-discharge cycles is calculated until an end voltage of 2.0 V.

Carbons exhibiting hysteresis show poor cycling performance, and can be discharged only in a broad potential region of about 1-2 V (Fig. 13) [41, 51, 52, 218-220, 234-236, 244, 277, 278, 287], As a result, the energy efficiency of a lithium-ion cell is reduced. 

SEM representative images of the surface treated natural graphite SLC-1015 and its untreated precursor SL-20 are shown by Figure 1. The graphite particles with the rounded edges having less active sites tend to limit the reaction on its surfaces and thus improve its cycling performance and safety. 

As it is seen from the data of Figure 8, all modified materials have poor cycling performance their reversible capacities fade faster than the one of initial non-modified material, and become lower after the first 8-10 charge-discharge cycles. Thus, we can conclude that no positive effect is achieved by means of modification of the Carbon-Type material with bimetal tri-nuclear complex of Co(III)-Ni(II). 

CdS growth, by EC-ALE, has been studied by more groups than any other compound (Table 1) [111, 123, 143, 145, 154, 163, 165, 167-169, 172, 186], Initial EC-ALE studies by this group of CdS were performed with a TLEC (Figure 13), to determine potentials for a cycle [145]. Cd and S coverages were determined coulometrically for deposits as a function of the numbers of cycles performed. The dependence of thickness on the Cd deposition potential, for CdS deposits, revealed a plateau between —0.3 and —0.55 V, with the best deposits formed at —0.5 V, using a 10 mM CdSCL solution, pH 5.9 and an 11 mM, pH 11 Na2S solution. Reductive UPD was used for the Cd atomic layers and oxidative UPD for S. 

Figure 11. Effect of Ce on the cycled performance of a Rh/Als03 catalyst fed CO/Os mixtures at 550°C and a space velocity of 104,000 h 1 (39).

Tewe 00, Maner JH. 1981a. Long-term and carry-over effect of dietary inorganic cyanide (KCN) in the life cycle performance and metabolism of rats. Toxicol Appl Pharmacol 58 1-7. 

The lithium-storage properties of these Si SiOx/C nanocomposite electrodes were investigated in different electrolyte systems and compared to pure Si nanoparticles. From all the analyzed systems, the Si SiOx-C nanocomposite in conjunction with the solvent vinylene carbonate (VC) to form the solid-electrolyte interface showed the best lithium storage performance in terms of a highly reversible lithium-storage capacity (1100 mAh g-1), excellent cycling performance, and high rate capability (Fig. 7.9). 

ZnO [79] have been used in ECs. These hybrids all show enhanced electrochemical performance in terms of the high reversible capacity of LIBs or specific capacitance of ECs, rate capability, and cycling performance. 

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