Das Glycocoll ist seit 67 Jahren bekannt. Man hat es aus natiirlich vorkommenden Stoffen abscheiden und kiinstlich darstellen konnen. Man weiss, dass das Glycocoll ein Abkommling der Essigsaure ist, in welcher ein Methylwasserstoffatom durch Amid vertreten ist, und man stellt es als Prototyp aller Amidosauren hin, weil es in umfangreichem Maasse die Fahigkeit besitzt, mit Basen, S'auren und Salzen Verbindungen einzugehen. Trotz alledem war man der Entrathselung zahlreicher eigenthumlicher physikalischer und chemischer Eigenschaften dieser Substanz niemals naher gekommen. Man kannte weder ihre Molekulargrosse , noch diejenige ihrer Verbindungen. Das Glycocoll musste, seiner Abstammung gemass, als eine Saure aufgefasst werden, und doch schienen sich der Darstellung der gewohnlichen Derivate , welche die Saurenatur eines organischen Korpers documentiren wie der A ether , des Amids, aussergewohnliche Schwierigkeiten entgegen zu stellen, Eigenschaften, welche mit der Definition des Glycocolls als Ainidoessigsaure nicht unmittelbar in Einklang zu bringen waren. Wir begegnen daher schon friihzeitig 1) der Vermnthung. dass das Glycocoll eine Vereinigung von wenigstens zwei Molekulen Amidoessigsaure reprasentire, welche mit Hulfe des funfwerthig gewordenen Stickstoffs der Amidogruppe zu einem ammonsalzartigen K orper verbunden seien. Welche Molekulargrosse dieser Saure nun in der That zukommt, liisst sich nicht entscheiden, da dieselbe erst unter volliger Zersetzung bei unverhaltnissmassig hoher Temperatur schmilzt. Es schien deshalb wunschenswerth, zunachst Derivate dieser Saure darzustellen, deren Molekulargrosse festgestellt werden konnte, deren Eigenschaften aber,--I) S t r e c k e r : Ann. Chein. 65, 130.

The processes taking place during the discharge of Li/SOC12/C cells were studied. Test vehicles included wound D, bobbin configuration 2D cells, and 2000 A-hr prismatic cells. Dried cathodes taken from 2D cells, discharged at 150 mA were analyzed quantitatively for lithium-sulfur oxyaeid salts. Little or no such salt was found for cells discharged at ambient temperature. Measurements of the open-circuit voltage of this system as a function of temperature showed essentially linear dependence with positive slope between ~-72 ~ and --20~ but the voltage fell more steeply as the temperature approached --60~Appearance of a nonvolatile reducing species occurred in the cathodes of cells discharged at --20~ which were not present in cathodes from cells discharged at higher temperature. Controlled potential electrolysis of supporting electrolytes containing limited amounts of SOCI.~ were carried out between 0 ~ and 25~ The electrical equivalent of thionyl chloride was found to be between 1.5 and 2.0 F/mole. The 200,0 A-hr cells were used to measure dissolved SO2 and SO2 escaping at atmospheric pressure and ambient temperature from anode-limited and cathode-limited cells. The amount of SO2 produced was found to be only a fraction of that predicted by 4Li ~-2SOCls -+ S § SO2 + 4LiC1 until near the end of discharge. The total amount of SOs produced by the end of discharge was not more than predicted by this reaction. Vented, anode-limited cells did not release SO2 while cathode-limited cells did. Temperature cycling of electrolyte taken from cells immediately after discharge was carried out in a sealed vessel. Pressure hysteresis occurred, which could not be duplicated with simulated used electrolyte made with S, SOs, SOC12, LiA1C14, and cathode material. At --20~ and below, the discharge reaction 8Li + 3SOCls-~ 2S ~-Li2SO8 ~-6LiC1 may be significant, while at temperatures higher than this, the reaction 2nLi + nSOC12-~ 2nLiC1 + (SO), may predominate, where the (SO)n remains in solution. Slow decomposition according to (SO)h-> (n/2)S + (n/2)SOz may subsequently take place.

The lithium-sulfur dioxide rechargeable system has been investigated with LiAlC14 electrolyte in hermetically sealed experimental cells. Over 50 cells were tested at 1-6 mA/cm2 discharge and 0.5-2 mA/cm2 charge rates using carbon cathode material to evaluate cycle life and capacity at ambient (21OC) and low (-30°C) temperatures. Most of the cells delivered excellent cycle life with significantly higher capacity than that reported in the literature.Optimization of the cathode process, cell configuration and electrochemical voltage limits were critical in obtaining high cell capacity and cycle life.Scanning electron micrographs and energy dispersive X-ray spectra of charged and discharged anodes show the presence of cubic salt crystals containing chlorine but no aluminum or sulfur. These data strongly suggest that LiCl is formed on the anode surface. A n amorphous second phase was detected on the surface with a constant SIA1 atomic ratio. Examination of charged and discharged cathodes by X-ray diffraction confirms LiCl as the sole crystalline discharge product.

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