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We report that a solid-state battery architecture enables the reversible, four electron storage of fully utilized solvothermally synthesized cubic-FeS2 (pyrite). With a sulfide based glass electrolyte we successfully confine electro-active species and permit the safe use of a lithium metal anode. These FeS2/Li solid-state cells deliver a theoretical specific capacity of 894 mAh g−1 at 60 °C. We find that nanoparticles of orthorhombic-FeS2 (marcasite) are generated upon recharge at 30-60 °C which explains a coincident change in rate kinetics. [ABSTRACT FROM AUTHOR]

Cycle stability of solid-state lithium batteries (SSLBs) using a LiCoO2 cathode is improved by atomic layer deposition (ALD) on active material powder with Al2O3. SSLBs with LiCoO2/Li3.15Ge0.15P0.85S4/77.5Li2S-22.5P2S5/Li structure were constructed and tested by charge-discharge cycling at a current density of 45 μA cm-2 with a voltage window of 3.3 ~ 4.3 V (vs. Li/Li+). Capacity degradation during cycling is suppressed dramatically by employing Al2O3 ALD-coated LiCoO2 in the composite cathode. Whereas only 70% of capacity retention is achieved for uncoated LiCoO2 after 25 cycles, 90% of capacity retention is observed for LiCoO2 with ALD Al2O3 layers. Electrochemical impedance spectroscopy (EIS) and transmission electron microscopy (TEM) studies show that the presence of ALD Al2O3 layers on the surface of LiCoO2 reduces interfacial resistance development between LiCoO2 and solid state electrolyte (SSE) during cycling. [ABSTRACT FROM AUTHOR]

To deploy solid-state Li batteries in next-generation vehicles, it is essential to develop electrodes with durability, high energy and high power. Here we report on nanostructured composite cathode materials that enable solid-state Li batteries to cycle with durable high energy and high rate performance. Particle size of TiS2 is reduced by planetary ball-milling to enhance performance of nanocomposite cathodes in solid-state Li batteries. The better utilization of active material and fast kinetics resulting from the size reduction of TiS2 allow for highly reversible capacity in both room temperature and elevated temperature batteries. High power all-solid-state batteries have been constructed with nano-sized TiS2 and demonstrated high power density over 1000 W kg-1 for over 50 cycles, with a maximum power density of ~ 1400 W kg-1. Galvanostatic intermittent titration technique and electrochemical impedance spectroscopy are employed in order to explain the extremely high rate capability of nanostructured TiS2 nanocomposite. [ABSTRACT FROM AUTHOR]

Abstract: We report on a novel method for in situ lithiation of lithium free TiS2 using Li3N in an all-solid-state battery configuration. This method was tested using a Li3N–TiS2–80Li2S:20P2S5 composite positive electrode and an indium metal negative electrode. It is shown that approximately 37% of Li3N spontaneously decomposes during composite preparation regardless of the composition. Solid-state battery cells built with a 3:1 stoichiometric ratio of Li:Ti demonstrated a high 1st cycle charge capacity of 287mAhg−1, 20% greater than the theoretical capacity of TiS2 at 239mAhg−1. The difference provides an excess capacity in the indium metal negative electrode. [Copyright &y& Elsevier]

Abstract: Glass–ceramic and glass Li2S–GeSe2–P2S5 electrolytes were prepared by a single step ball milling (SSBM) process. Various compositions of Li4−x Ge1−x P x S2(1+x)Se2(1−x) with/without heat treatment (HT) from x =0.55 to x =1.00 were systematically investigated. Structural analysis by X-ray diffraction (XRD) showed gradual increase of the lattice constant followed by significant phase change with increasing GeSe2. HT also affected the crystallinity. Incorporation of GeSe2 in Li2S–P2S5 kept high conductivity with a maximum value of 1.4×10−3 Scm−1 at room temperature for x =0.95 in Li4−x Ge1−x P x S2(1+x)Se2(1−x) without HT. All-solid-state LiCoO2/Li cells using Li2S–GeSe2–P2S5 as solid-state electrolytes (SE) were tested by constant-current constant-voltage (CCCV) charge–discharge cycling at a current density of 50μAcm−2 between 2.5 and 4.3V (vs. Li/Li+). In spite of the extremely high conductivity of the SE, LiCoO2/Li cells showed a large irreversible reaction especially during the first charging cycle. LiCoO2 with SEs heat-treated at elevated temperature exhibited a capacity over 100mAhg−1 at the second cycle and consistently improved cycle retention, which is believed to be due to the better interfacial stability. [Copyright &y& Elsevier]