Energy storage is vital for realizing an energy independent future currently dominated by exploiting natural reserves supplemented by oil and gas exports. Since the commercialization of the first Li-ion battery (LIB) by Sony in 1991, there has been tremendous progress in the areas of cathode, electrolytes as well as anodes [1]. While lithiated transition metal oxides are still the flagship cathode systems largely focused on intercalation chemistry, newer chemistries exploiting alloying and zintl phase formation has been explored for use of silicon as an alternative anode. Similarly, there has been tremendous research in the area of alternative energy storage systems beyond lithium-ion intercalation chemistry. Lithium-sulfur batteries (LSB) as well as well as Li metal anodes have accordingly been the spotlight of much research activity in recent years. All systems are plagued by intransigent electronic conductivity and voltage-specific phase transition related kinetic limitations and physico-electrochemical challenges. Nano-engineered approaches appear primed for overcoming these hurdles.

We have thus, embarked on implementing dynamic theoretical and experimental strategies to develop engineered electronic and ionic conducting nanomaterials showing considerable promise. We have also developed myriad concepts over the years related to ex-situ synthesis of active-inactive nanocomposites, use of nanoscale droplets, nanoparticles, hollow Si nanotubes (h-SiNTs), cost-effective template derived nanoscale morphologies, scribable and flexible hetero-structured architectures displaying impressive capacities as high as ~3000 mAh/g with sustained cyclability and high rate capability in Si anodes[2]. Similarly, engineering approaches were implemented for generating sulfur cathodes in LSBs exploiting harnesses of inorganic, nanocomposite, tethered, and polymeric lithium ion conducting (LIC) matrices along with novel fine yarn-like and tethered architectures yielding 5.5 mAh/cm² – 12 mAh/cm² areal capacity as well as ~1200 mAh/g specific capacity with sulfur loadings as high as 20 mg/cm² displaying up to 250 cycles cycling stability[3]. Engineered novel Li metal anodes are also studied as alternative safe anodes. Results of these studies will be discussed. Finally, the presentation will address the bright future of tailored functional engineered systems in the rapidly evolving digitized global internet era of the 21^st century and the tremendous prospects for energy independence.

References

1. Wang, P.N. Kumta, et al. ACS Nano (2011);
2. Gattu, P.N. Kumta et al. Nano Research (2017)
3. M. Shanthi, P.N. Kumta et al. Electrochimica Acta (2017)