Negative electrode preparation

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. 

Whereas there had been a significant amount of work on the properties of lithium alloys in the research community for a number of years, this alternative did not receive much attention in the commercial world until about 1990, when Sony began producing batteries with lithium-carbon negative electrodes. Since then, there has been a large amount of work on the preparation, structure, and properties of various carbons in lithium cells. 

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. 

Nakahara et al. (4) prepared an electricity storage device consisting of poly(2,2,5,5-tetramethylpyrrolidinoxy methacrylate), (VII), for use as a negative electrode in lithium secondary batteries. 

A negative electrode was prepared by the author [4] that consisted of 70% poly (9-fluroenone) or poly(cyclopent[def fluorene, 8-dione), (1), with 25wt% acetylene black and 5 wt% tetrafluoroethylene using LiAsFg as the electrolyte in propylene carbonate. 

Figure 3.29. Scanning electron microscope picture of the electrode-electrolyte structure along a perpendicular cut. Top screen-printed Lao.jSro 4CO0 FeogOj positive electrode. Middle spray-deposited electrolyte, YSZ = 8 mol% YjOg stabilised ZrOj. Bottom negative electrode, NiO and YSZ in ratio 7 3, in cermet CeOj. (From D. Perednis and L. Gauckler (2004). Solid oxide fuel cells with electrolytes prepared via spray pyrolysis. Solid State Ionics 166,229-239. Reprinted by permission from Elsevier.)...

Thus, in analogy with the monomer quinone/hydroquinone redox couple, two electrons per monomer unit are assumed to be transferred finally. Examples for lithium metal negative electrodes in combination with PANI are reported in [508-510]. Details of the preparation of PANI positive electrodes are given in the patent literature (e.g., [358, 511-513]). 

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