Composite lithium anode

Desjardins and MacLean [102] studied a composite of Hthium and Li3N named Linode. Their research cell showed improvements in cycle Hfe, shelf life, and electrode morphology after cycHng. 

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 [103]. Their idea is based on the recombination of dead lithium and formation of many active sites for 

We believe that the advantage of these composite anodes is that they result in a uniform Hthium deposition at the boundaries of two components that may improve 

It is generally considered that the lithium surface fihn is produced by a reaction between the lithium and the electrolyte materials. However, by XPS we have detected vanadium on a lithium anode surface cycled for Li/a-V205-P20s cells with EC-based electrolytes [81]. Vanadium comes from the partially dissolved discharge product, LixV20s, in the electrolyte. Then, with a Ii/a-V205 cell, the cathode also affects the chemical composition of the surface film [104]. 

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Figure 6. Lithium cycling efficiency of composite lithium anodes in an Li/a -V205 coin-type cell (thickness 2 mm, diameter 23 mm) with 1.5 mol L 1 LiAsF6 - EC/2MeTHF. ...

There have been many attempts to improve the cycling efficiency of lithium anodes. We describe some of them below, by discussing electrolytes, electrolyte additives, the stack pressure on the electrode, composite anodes, and alternatives to the lithium-metal anode anode. 

Veeraraghavan, B., Paul, J., Haran, B., and Popov, B., Study of polypyrrole graphite composite as anode material for secondary lithium-ion batteries, J. Power Sources, 109, 377, 2002. 

Lin, H.J.,Weng, W, Ren, J., Qiu, L.B., Zhang, Z.T., Chen, P.N., Chen,X.L., Deng, J., Wang, Y.G., Peng, H.S., 2014. Twisted aligned carbon nano tube/ silicon composite fiber anode for flexible wire-shaped lithium-ion battery. Adv. Mater. 26,1217-1222. 

Tho, S., Yue, W, Zhong, M., Chen, Z., and Ren, Y. [2014]. Fabrication of graphene-encapsulated porous carbon-metal oxide composites as anode materials for lithium-ion batteries, ACS Appl. Mater. Interfaces, 6, pp. 6332-6339. 

Shu J, Li H, Yang R, Shi Y, Huang X (2006) Cage-like carbon nanotubes/Si composite as anode material for lithium ion batteries. Electrochem Commun 8 51-54... 

Zheng Y, Yang J, Wang JL, NuLi YN (2007) Nano-porous Si/C composites for anode material of lithium-ion batteries. Electrochim Acta 52 5863-5867... 

Carmer JLG, Morales J, Sanchez L (2008) Nano-Si/cellulose composites as anode materials for lithium-ion batteries. Electrochem Solid-State Lett 11 A101-A104... 

The theoretical capacity of metallic lithium is much higher than that of lithiated carbon material having a composition of LiCg. The advantage of the higher capacity of metallic lithium is reduced because a three- to fivefold excess of lithium is required in rechargeable batteries having metallic lithium anodes to achieve a reasonable cycle life. The comparison is shown in Table 34.4. 

Lithium Carbon Batteries. These batteries are made in an hermetically sealed stainless-steel container with a metallic lithium anode, a Ketjen black carbon cathode, and a LiAlCl4 6SO2 electrolyte. The cathode composition is 96% Ketjen black and 4% Teflon. Teflon-rich carbon-coated nickel exmet is used as the cathode substrate. These batteries are made cathode-limited with the anode capaeity at least twiee the cathode capacity. Batteries are vacuum filled with the electrolyte. The open-eireuit voltage of the system is about 3.3 V. The average discharge voltage is 3.1 V at 1 mA/em. It is heheved that high-surface-area carbon forms a complex with the electrolyte, and this eomplex takes part in the cell reaction. 

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