Next generation energy storage devices for stationary as well as mobile electronics will not only need high gravimetric and volumetric capacity, but also long term stability even in rough environments at elevated temperature. Here, all solid state batteries based on Li-garnet structures are shown as interesting model systems that: i.) can partially use industrial waste heat to increase charging times (increased Li⁺ diffusion) for stationary, ii.) can integrate new high capacity electrode materials which show conventionally a low stability in standard liquid/polymer based Li-batteries, iii.) are easy transferrable to model thin film battery structures for powering of portable electronics. Going all-solid-state opens up completely new pathways for chip integration and downscaling to the sub-micron range for high energy densities to battle supercapacitors. From a materials perspective, cubic garnet Li₇La₃Zr₂O₁₂-based structures are among the fastest conducting solid state electrolytes^[1]. Moreover, their inherent compatibility with metallic Lithium, stability in a wide voltage range as well as their Arrhenius-activated conduction mechanism support their prospering interest for all solid state large-scale and future microbatteries. On the electrode side, Li₄Ti₅O₁₂ is known as one of the most stable anode material due to its remarkably low volume expansion upon lithiation/delithiation and its good cycle performance ^[2].

We hereby report our latest progress on nanostructuring different promising anode thin films of Li₄Ti₅O₁₂ / TiO₂ mixed-phase deposited by pulsed laser deposition and constructed bilayer half-cells batteries systems with Li₇La₃Zr₂O₁₂ pellets as the electrolyte. Rate capability studies as well as galvanostatic cycling of this system showed promising initial capacity and acted as a case study for the well-known Li₄Ti₅O₁₂ thin film anode, shown its good compatibility with the investigated solid garnet electrolyte. Near-order phenomena could be tracked by Raman spectroscopy and gave insight into the process of lithiation and delithiation. To the best of our knowledge, no such study has yet been reported in literature. However, degradation and ageing effects still remain challenging and will be discussed.

References

^[1] Thangadurai et al., Chemical Society Reviews 43(13), 4714.

^[2] Kumantani et al. Applied Physics Letters 101(12), 123103.