Negative electrodes composition

The characteristics of ECPs can be significantly increased by the formation of composites between ECPs and other materials, for example, carbon (including carbon nanotubes), inorganic oxides and hydroxides, and other metal compounds. Examples of some such composites and their electrochemical characteristics are given in Table 28.4. Such electrodes can be used to manufacture symmetrical devices (type I or type in) of the same positive and negative electrodes. Composite materials... 

The general configuration of one system that has reached an advanced stage of development (22) is shown in Figure 1. The negative electrode consists of thin lithium foil. The composite cathode is composed of vanadium oxide [12037-42-2] 6 13 with polymer electrolyte. Demonstration... 

The lithium-silicon system has also been of interest for use in the negative electrodes of elevated-temperature molten salt electrolyte lithium batteries. A composition containing 44 wt.% Li, where Li/Si=3.18, has been used in commercial... 

SEM images indicate that both graphite samples have very similar morphologies. Negative electrode laminates with active materials of SL-20 and SLC-1015 were then prepared using similar compositions. These laminates were then used to prepare negative electrodes that were inserted into Li-ion cells having similar cathodes and electrolyte materials. 

The following chapter contains a collection of six papers specifically dedicated to the topic of metal/graphite composites as candidate active materials for the negative electrodes of the lithium-ion batteries of the near future. Editors believe this chapter to be a very first attempt made in the worldwide electrochemical literature to group metal/graphite composite lithium-ion battery developers into a stand-alone section of a book. 

In conclusion, the composite formed by a carbon fiber cloth coated with pyrocarbon is a very promising material for the negative electrode of lithium batteries, since it couples a high reversible capacity due to the disordered fiber (1.5 time the graphite value) with a small irreversible... 

The study on the characterization of alkaline silver-zinc cells and composite electrodes for such cells was carried out [349, 350]. The improved silver-zinc battery with new developments in additives (Bi203) to the negative electrode and separator coatings for underwater... 

The next layer beyond the specifically adsorbed layer is rich in cations attracted by the negative electrode. The excess of cations decreases with increasing distance from the electrode. This region, whose composition is different from that of bulk solution, is called the diffuse part of the double layer and is typically 0.3-10 nm thick. The thickness is controlled by the balance between attraction toward the electrode and randomization by thermal motion. 

As a matter of fact, this is the basis for the electrorefining of metals. The impure metal electrode (say, Cu) is used as the positive electrode, and a piece of pure Cu metal is used as the negative electrode the solution is CuS04. The composition of the solution is so designed, and the applied voltage so chosen, that the impurities stay in solution or precipitate out, and only copper plates out at the negative electrode ... 

Some other asymmetric devices have been proposed implying a LTO negative electrode and alternative positive electrode materials as (1) conducting polymers and (2) battery-like material/ activated carbon composites. 

The same occurs when a Li[Mnj j Nio 5 yMex+)]04/carbon composite is used as positive electrode in combination with LTO as negative one [108,110], Figure 8.31 shows that the maximum cell voltage reaches 3.5 V, but the cyclability of the device is very poor. Even if activated carbon is used as negative electrode in combination with a Li-based compound similar to the previous one (LiMnj 2Ni0 504) for the positive electrode [109], the maximum cell voltage is only 2.8 V and the cyclability and power capability are not improved. 

Among diverse alloys, amorphous Sn composite oxide (ATCO) reported by Fuji photo film has caused a great deal of renewed interests in Li alloys as an alternative for use in the negative electrode of Li-ion batteries [176,177]. The ATCO provides a gravimetric capacity of >600mAh/g for reversible Li adsorption and release, which corresponds to more than 2200mAh/cm3 in terms of reversible capacity per unit volume, that is, about twice that of the carbon materials. 

---