Solid-state electrolyte lithium batteries

It is now well established that solvent-free films can be cast from solutions of polyethers (such as poly(ethylene oxide)) and alkali metal salts, and that these films can display high ionic conductivity. Most of the effort devoted to this field has been based on the potential of such materials as solid-state electrolytes for battery applications. In this context, from viewpoints of both ionic mobility and weight, lithium salts in PEO have attracted the most intensive research and appear to offer the most promise such materials are discussed elsewhere. The preparation of materials displaying both electronic and ionic conductivity raises interesting possibilities both in the field of batteries and sensors and is beginning to attract attention (16). 

Application of Glass Electrolytes to Solid-State Rechargeable Lithium Batteries... 

The second type of a glassy battery operating at ambient temperatme is the lithium battery, involving a lithium metal anode and a titanium disulfide (TiS2) cathode, with a vitreous solid state electrolyte. Such batteries have been developed first by SAFT in France, and then by Union Carbide in the U.S. They are conunercialized by the two companies. 

Bridged polysilsesquioxanes having covalently bound acidic groups, introduced via modification of the disulfide linkages within the network, were studied as solid-state electrolytes for proton-exchange fuel cell applications.473 Also, short-chain polysiloxanes with oligoethylene glycol side chains, doped with lithium salts, were studied as polymer electrolytes for lithium batteries. 

If GO is used as a host lattice for Li+ in aprotic electrolytes, reversibility is improved [577]. The potential level is distinctly more positive than with donor GIC, at about —1 V vs. SHE. An all-solid-state Li/GO battery with PE0/LiC104 as solid electrolyte was reported by Mermoux and Touzain [578], but rechargeability is poor. Recently, the structure of graphite oxide was studied by its fluorination at 50-2()0 °C [579]. C-OH bonds were transformed into C-F bonds. The examples, in conjunction with Section 2, show that the formation or cleavage of covalent C-O (C-F) bonds makes the whole electrochemical process irreversible. Application was attempted in lithium primary batteries, which have a voltage of 2-2.5 V. Really reversible electrodes are only possible, however, with graphite intercalation compounds, which are characterized by weak polar bonds. 

Figure 6.16 Comparison of material costs for solid-state LPB and liquid electrolyte lithium batteries. From ref [30] by permission of the author.

Zheng J, Gu M, Chen H, Meduri P, Engelhard MH, Zhang J-G, Liu J, Xiao J (2013) Ionic liquid-enhanced solid state electrolyte interface (SEI) for lithium-sulfur batteries. J Mater Chem A l(29) 8464-8470. doi 10.1039/c3tal 1553d... 

Solid state electrolytes are also used, mainly in special long lasting batteries for extremely low loads, like lithium/LiJ/iodine batteries that are applied in pacemakers. High load batteries are the two examples, in Lines 11 and 12 of Table 1.1, based on sodium as active material in the negative electrodes. Both have been developed... 

Lithium-iodine (Li-Ij) batteries were specifically designed and developed for medical applications. These batteries consistently demonstrated the best performance and suitability, particularly for pacemakers, over a period exceeding 25 years. This particular battery is high in energy density but low in power level. Li-Ij is a low-conductivity solid-state electrolyte, which limits the current to a few microamperes. According to the manufactures, an operational life ranging from 7 to 12 years for this battery has been demonstrated in the field. The battery suppliers claim that these batteries could be used in other applications, such as watches and memory-retention devices. 

The battery chemistry is composed of solid-state films and uses Uthium-phosphorus-oxynitride (LiPON) solid-state electrolyte developed by Oak Ridge National Laboratory. The cathode is made from LiCo02 and the anode uses a very small amount of lithium metal. 

Solid-State Electrolytes. True all solid-state ionic electrolytes such as lithium phosphorus oxynitride (LiPON) provide adequate conductivity for use in thin film solid-state batteries (see Sec. 35.8.)... 

The polymer electrolyte lithium batteries contain aU solid-state components lithium as the anode material, a thin polymer film as a solid electrolyte and separator, and a transition metal chalcogenide or oxide, or a sulfur-based polymer as tbe cathode material. These features offer the potential for improved safety because of tbe reduced activity of lithium with the solid electrolyte, flexibility in design as tbe cell can be fabricated in various sizes and shapes, and high energy density. 

A specialized type of Li-ion battery developed for semi-conductor and printed circuit board (PCB) applications are thin-film, solid-state devices. These batteries which employ ceramic negative, solid electrolyte and positive electrode materials, can sustain high temperatures (250°C), and can be fabricated by high volume manufacturing techniques on silicon wafers which are viable as on-chip or on-board power sources for microelectronics. Batteries of this type can be very small, 0.04 cm x 0.04 cm x 2.0 fjm. For microelectronics applications, all components must survive solder re-flow conditions, nominally 250°C in air or nitrogen for 10 minutes. Cells with liquid or polymer electrolytes cannot sustain these conditions because of the volatility or thermal stability of organic components. Further, cells that employ lithium metal also fail as solder re-flow conditions exceed the melting point of lithium (180.5°C). 

Among the potential battery systems beyond Li-ion, the Li-air and Li-S batteries best meet the requirements of high energy density, low cost, and environmental friendhness. However, grand challenges remain, especially for the Li-air batteries. In near future, the Li-S batteries may be a better choice than the Li-air batteries although their problems have lasted for many years and have not yet been completely solved. Solid state electrolyte completely avoids the dissolution of lithium... 

Rhodes, C.P. (2011) Solid-state lithium batteries using thio-LISICON solid-state electrolytes. Available at http //www.oml. gov/ccsd registrations/battery/abstracts/ Solid. 

At the time of writing, the solid-state alkali metal battery is by far the most important projected application of a polymer electrolyte. This is based on a thin film laminated structure containing a lithium-metal negative electrode, a polymer film electrolyte, and a positive electrode made of an oxidizing agent capable of inserting alkali ions into its structure (Figure 7). 

Key words composite polymer electrolyte, lithium battery, all solid state battery, surface treatment, ceramic filler, polymer-in-ceramic composite. 

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