ИСТИНА

At present rapidly evolving technologies require increasingly sophisticated energy storage equipment for the creation of next-generation high-energy and high-power cells. Lithium metal (Li) is considered to be the most perspective anode material (with the lowest negative electrochemical potential – 3.040 V vs. the standard hydrogen electrode, high theoretical specific capacity – 3860 mA h/g, and low density – 0.59 g/cm3) for the rechargeable lithium battery systems including the highly promising energy storage Li–sulfur, Li–air, and Li–graphene systems and Li metal batteries with (utilizing) intercalation compound cathodes with exceptionally high theoretical energy and power densities (3 500 W h/kg for Li–air) that is about ten times higher than the best current lithium-ion batteries with graphite anode (200 W h/kg)[1,2,3]. Nevertheless the main reason preventing commercialization of rechargeable lithium metal batteries since they have been proposed in the middle of 80-s arises in connection with the a high propensity to form Li dendrites (tree-like structures) at the anode upon repeated charges/discharges processes resulted in internal short-circuiting and a low Coulombic efficiency (CE) connected with a short cycle life. The mechanism of dendrite initiation and propagation can be explained in terms of The Chazalviel electromigration-limited model based on its results the dendrite suppression can be achieved using electrolyte with high ionic conductivity and a Li+ transference number (tLi+) close to unity[4]. High shear modulus is also an important property for a functional electrolyte to suppress the Li dendrite growth. On this basis our research group suggested using polymer electrolyte systems with solid-state Li-ion conductor NafionLi+ Next aim is to realize Li-metal anode in operand reflectometry measurements of the SEI layer and dendrite formation as function of potential in a working lithium special designed cell and then on a real operating Li-Nafion polymer system. Neutron reflectometry, NR, determines the depth profile of the scattering length density, SLD (which is related to composition), by fitting the intensity of reflected neutrons as a function of grazing angle from the surface, θ, providing sub-Ångström precision of features greater than ∼1.5 nm in thickness.