Lithium anode for

Sion Power Lithium anodes for electrochemical cells... 

Imanishi N, Hasegawa S, Zhang T, Hirano A, Takeda Y, Yamamoto O (2008) Lithium anode for lithium-air batiraies. J Power Sources 185 1392... 

Lead Telluride. Lead teUuride [1314-91 -6] PbTe, forms white cubic crystals, mol wt 334.79, sp gr 8.16, and has a hardness of 3 on the Mohs scale. It is very slightly soluble in water, melts at 917°C, and is prepared by melting lead and tellurium together. Lead teUuride has semiconductive and photoconductive properties. It is used in pyrometry, in heat-sensing instmments such as bolometers and infrared spectroscopes (see Infrared technology AND RAMAN SPECTROSCOPY), and in thermoelectric elements to convert heat directly to electricity (33,34,83). Lead teUuride is also used in catalysts for oxygen reduction in fuel ceUs (qv) (84), as cathodes in primary batteries with lithium anodes (85), in electrical contacts for vacuum switches (86), in lead-ion selective electrodes (87), in tunable lasers (qv) (88), and in thermistors (89). 

The work presented in this chapter involves the study of high capacity carbonaceous materials as anodes for lithium-ion battery applications. There are hundreds and thousands of carbonaceous materials commercially available. Lithium can be inserted reversibly within most of these carbons. In order to prepare high capacity carbons for hthium-ion batteries, one has to understand the physics and chemistry of this insertion. Good understanding will ultimately lead to carbonaceous materials with higher capacity and better performance. 

Fig. 25. Voltage versus capacity for the second discharge and charge of cells with lithium anodes and with cathodes made of Br-series samples. The curves have been sequentially offset for clarity. The shifts are Br700, 4.0V BrS OO, 3 OV Br900, 2 OV BrlOOO, l.OV, and BrllOO, 0.0V.

J.R. Dahn, A.K. Sleigh, Hang Shi, B.W. Way, W.J. Weydanz, J.N. Reimers, Q. Zhong, and U. von Sacken, Carbons and Graphites as Substitutes for the Lithium Anode , in Lithium Batteries, G. Pistoia, Elsevier, North Holland (1993). 

Cylindrical batteries can be classified into two basic types one with a spiral structure, and one with an inside-out structure. The former consists of a thin, wound cathode and the lithium anode with a separator between them. The latter is constructed by pressing the cathode mixture into a high-density cylindrical form. Batteries with the spiral construction are suitable for high-rate drain, and those with the inside-out construction are suitable for high energy density. 

Table 3). However, their cycle life depends on the discharge and charge currents. This problem results from the low cycling efficiency of lithium anodes. Another big problem is the safety of lithium-metal cells. One of the reasons for their poor thermal stability is the high reactivity and low melting point (180 °C) of lithium. 

Many studies have been undertaken with a view to improving lithium anode performance to obtain a practical cell. This section will describe recent progress in the study of lithium-metal anodes and the cells. Sections 3.2 to 3.7 describe studies on the surface of uncycled lithium and of lithium coupled with electrolytes, methods for measuring the cycling efficiency of lithium, the morphology of deposited lithium, the mechanism of lithium deposition and dissolution, the amount of dead lithium, the improvement of cycling efficiency, and alternatives to the lithium-metal anode. Section 3.8 describes the safety of rechargeable lithium-metal cells. 

Lithium deposited on an anode during a charge is chemically active and reacts with organic electrolytes after deposition. Then, the lithium is consumed during cycling. The cycling efficiency (percent) of a lithium anode (Eff) is basically defined by Eq. (1) [23], where Qp is the amount of electricity needed to plate lithium and <2S is the amount of electricity needed to strip all the plated lithium. As Eff is less than 100 percent, an excess of lithium is included in a practical rechargeable cell to compensate for the consumed lithium. 

Later, Saito et al. [58] studied anodes with a layered structure consisting of Li/ protective film/additive/protective film/Li/ protective film/additive/ -. They made the anode by dropping the additive on a lithium sheet, folding the lithium sheet, and then compressing the folded lithium with an oil press. They repeated this process more than ten times. The FOM in LiAsF6-EC/2MeTHF electrolyte was 7.41, 13.5, and 37.0 for a lithium anode without additives, a lithium anode with toluene in the electrolyte, and a layered-structure lithium anode containing toluene, respectively. 

A lithium anode mixed with conductive particles of Cu or Ni was studied by Saito et al. they obtained an improvement in the cycling efficiency (Fig.6) [80]. Their idea is based on the recombination of dead lithium and formation of many active sites for deposition. 

V2O5-P205 (95 5, molar ratio) cathode and a lithium anode (Li/a-V205 cell) [1]. In this section, we describe safety test results for AA Li/a- V2Os cells. The AA cell we fabricated has a pressure vent, a Polyswitch (PS, Raychem Co., thermal and current fuse) and is composed of a spirally wound cathode sheet, a metallic Li-based anode sheet and a polyethylene (PE) separator [87]. 

With regard to rechargeable cells, a number of laboratory studies have assessed the applicability of the rocking-chair concept to PAN-EC/PC electrolytes with various anode/cathode electrode couples [121-123], Performance studies on cells of the type Li°l PAN-EC/PC-based electrolyte lLiMn20 and carbon I PAN-EC/PC-based electrolyte ILiNi02 show some capacity decline with cycling [121]. For cells with a lithium anode, the capacity decay can be attributed mainly to passivation and loss of lithium by its reaction with... 

Figure 20. SEI formation on different anodes for rechargeable Li batteries (A) lithium metal, (B) graphitic carbon, and (C) metals and intermetallics. Different colors of the SEI indicate SEI products formed at different stages of charge and discharge (and do not indicate different composition) [42],...

Composite electrodes made of two carbon components were evaluated experimentally as anodes for Li-ion batteries. The electrochemical activity of these electrodes in the reaction of reversible lithium intercalation ffom/to a solution of LiPF6 in ethyl carbonate and diethyl carbonate was studied. Compositions of the electrode material promising for the usage in Li-ion batteries were found. 

EMERGING METAL/CARBON COMPOSITE ANODES FOR NEXT GENERATION LITHIUM-ION BATTERIES... 

Yang J., Winter M., Besenhard JO. Small particle size multiphase Li-alloy anodes for lithium-ion batteries. Solid State Ionics 1996 90 281-87. 

Turner R.L., Amik B., Krause L.J., Christensen L., Dahn J.R. Electrochemical Characteristics of Sn-Mo Anodes for Lithium Batteries. Proceedings of Joint (ECS ISE) International Meeting 2001 2-7 September San Francisco, 2 Abstract No. 257, 2001. 

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