Svetlana Menkin

On the way to high-conductivity single lithium-ion conductors

Solid electrolytes can potentially address three key limitations of the organic electrolytes used in today’s lithium-ion batteries, namely, their flammability, limited electrochemical stability and low cationic transference number. The pioneering works of Wright and Armand, suggesting the use of solid poly(ethylene oxide)-based polymer electrolytes (PE) for lithium batteries, paved the way to the development of solid-state batteries based on PEs. Yet, low cationic mobility–low Li+ transference number in polymer materials coupled with sufficiently high room-temperature conductivity remains inaccessible. The current strategies employed for the production of single-ion polymer conductors include designing new lithium salts, bonding of anions with the main polyether chain or incorporating them into the side chains of comb-branched polymers, plasticizing, adding inorganic fillers and anion receptors. Glass and crystalline superionic solids are classical single-ion-conducting electrolytes. However, because of grain boundaries and poor electrode/electrolyte interfacial contacts, achieving electrochemical performance in solid-state batteries comprising polycrystalline inorganic electrolytes, comparable to the existing batteries with liquid electrolytes, is particularly challenging. Quasi-elastic polymer-in-ceramic electrolytes provide good alternatives to the traditional lithium-ion-battery electrolytes and are believed to be the subject of extensive current research. This review provides an account of the advances over the past decade in the development of single-ion-conducting electrolytes and offers some directions and references that may be useful for further investigations.

Towards smart free form-factor 3D printable batteries

Continuous novelty as the basis for creative advance in rapidly developing different form-factor microelectronic devices requires seamless integrability of batteries. Thus, in the past decade, along with developments in battery materials, the focus has been shifting more and more towards innovative fabrication processes, unconventional configurations, and designs with multi-functional components. We present here, for the first time, a novel concept and feasibility study of a 3D-microbattery printed by fused-filament fabrication (FFF). The reversible electrochemical cycling of 3D printed lithium iron phosphate (LFP) and lithium titanate (LTO) composite polymer electrodes vs. the lithium metal anode has been demonstrated in cells containing conventional non-aqueous and ionic-liquid electrolytes. We believe that by using comprehensively structured interlaced electrode networks it would be possible not only to fabricate free form-factor batteries but also to alleviate the continuous volume changes occurring during charge and discharge.