“Lithium-Free” Thin-Film Battery with In Situ Plated Li Anode

Abstract

It is an old concept to fabricate lithium batteries in the discharged state with only an appropriate current collector as the negative electrode (anode). On the initial charge, metallic Li is electroplated at this anode current collector, and so, during electrochemical cycling, the battery operates as a Li battery which contains only the amount of lithium that is supplied by the positive electrode (cathode).Despite some improvements, 1 the manufacture of a practical, rechargeable Li battery that operates exclusively with an in situ plated Li anode has been prevented by the formation of mossy, dendritic, and granular metallic lithium deposits on metal foils. 2 In this paper, we report on the feasibility and electrochemical properties of a Cu/solid lithium electrolyte/LiCoO 2 thin-film battery, where Cu represents an anode current collector that does not form intermetallic compounds with lithium. Prior to the initial charge, all of the battery components are stable in air for several hours, which facilitates handling and processing of this "Li-free" lithium battery.During operation, this Li-free battery shows the maximum potential and high rate capability inherent in a Li battery but avoids the major drawbacks of a battery fabricated with a Li metal anode. The vapor deposition of a metallic lithium film is more complicated than the deposition of other metal films that are less air sensitive, and due to the low melting point of lithium (181ЊC) a Li battery does not survive the 250ЊC solder reflow process commonly used to assemble electronic circuit boards. 3 In this paper, we demonstrate that the Li free battery with an in situ plated Li anode shows no signs of degradation after being heated at 250ЊC in air for 10 min in the Li-free state. Furthermore, complete stripping of the electroplated Li anode is reversible, and since no excess Li is present, the Li-free battery cannot be destroyed by overdischarging the LiCoO 2 cathode, in contrast to a conventional Li-LiCoO 2 battery.The Li-free battery prior to operation resembles a Li-ion battery, which is also assembled in its fully discharged state. However, the Li-free battery avoids the capacity problem inherent to tin oxide-and oxynitride-based insertion materials 3-7 which have recently been proposed as anodes for Li-ion cells. These anodes are known to consume, irreversibly, between 40 and 60% of the lithium inserted during their electrochemical activation in the initial cycle due to the formation of an amorphous matrix containing Li 2 O or Li 3 N. [3][4][5]8 Despite the technically high capacity of these anodes, between 600 and 700 mAh/g, the unsatisfactory ratio of reversible to irreversible capacity severely limits the utilization of the cathode, which serves as the Li-ion cell's initial lithium source. Recently, we showed that the cathode utilization could be improved by fabricating cathodeheavy cells in which a good deal of the total reversible cell capacity was obtained by electrochemical plating and stripping of metallic lithium from the overlithiated anode ...

Dual Cation- and Anion-Based Redox Process in Lithium Titanium Oxysulfide Thin Film Cathodes for All-Solid-State Lithium-Ion Batteries

“…Therefore, lithium-ion or 'lithium-free' cell designs, 11,12 and consequently lithiated materials at the positive electrode, are preferably envisaged for microbatteries with improved performance. In this context, the aim of this study was to develop a new lithiated positive electrode material with possible 3 advantages over the widespread LiCoO 2 cathode material.…”

Flexible and biocompatible high-performance solid-state micro-battery for implantable orthodontic system

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Bulk-Type Lithium Metal Secondary Battery with Indium Thin Layer at Interface between Li Electrode and Li2S-P2S5 Solid Electrolyte

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