Defect-induced plating of lithium metal within porous graphene networks

Abstract

Lithium metal is known to possess a very high theoretical capacity of 3,842 mAh g À 1 in lithium batteries. However, the use of metallic lithium leads to extensive dendritic growth that poses serious safety hazards. Hence, lithium metal has long been replaced by layered lithium metal oxide and phospho-olivine cathodes that offer safer performance over extended cycling, although significantly compromising on the achievable capacities. Here we report the defect-induced plating of metallic lithium within the interior of a porous graphene network. The network acts as a caged entrapment for lithium metal that prevents dendritic growth, facilitating extended cycling of the electrode. The plating of lithium metal within the interior of the porous graphene structure results in very high specific capacities in excess of 850 mAh g À 1 . Extended testing for over 1,000 charge/discharge cycles indicates excellent reversibility and coulombic efficiencies above 99%.

Enhanced Li capacity in functionalized graphene: A first principle study with van der Waals correction

“…However, it would be possible to further increase the storage capacity by increasing the density of functional groups and Li atoms, i.e., by playing around with number of Li atoms per epoxy and/or per hydroxyl groups. Additionally, as both vacancy adsorption 7,13 and functionalization (current work) show enhanced Li adsorption, functionalization and defects together can further increase the capacity and lithiation potential. To accurately predict the capacity of GO, one has to investigate the possibility of phase segregation 41 in addition to the thermodynamic stability.…”

“…Circles represent data from previous literature with SW and DV defects in graphene. 7,13 A highest capacity of $860 mAhg À1 is obtained on GO with epoxy þ hydroxyl functionalization. and the singly bonded oxygen atom with graphene sheet at onsite position could be important factors for the boost in the LP with higher capacity.…”

Advanced Micro/Nanostructures for Lithium Metal Anodes

“…a) Preparation of porous graphene networks and the tests as lithium metal anode in lithium batteries. Reproduced with permission 47. Copyright 2014, Nature Publishing Group.…”

Anode Materials Based on Graphene for Lithium-Ion Batteries

“…Research results indicate values of intercalation capacity of graphene from 165 to 1400 mA•h•g -1 of that in the case of high values of capacitance are not consistent with the theoretical model of intercalation (inserts between layers)/deintercalation of lithium into the graphite structure [1]. However, some authors do attempts a theoretical explanation of the increased intercalation capacity of graphene compared to graphite [42][43][44][45] by the presence of defects in the structure of graphene flakes.…”