A Periodic “Self‐Correction” Scheme for Synchronizing Lithium Plating/Stripping at Ultrahigh Cycling Capacity

Abstract

Lithium (Li) metal can deliver the highest theoretical specific capacity among all lithium battery anodes, yet its application is significantly hindered due to a series of critical challenges (poor cycleability and safety risks, etc.), most of which are related to uncontrolled Li dendrite growth. However, the dendrite problem cannot be fully avoided because of a number of complicated multi-physical field factors, especially under high cycling rate and high capacity conditions. An ideal situation is when the battery can automatically restore the uncontrolled dendrites growth itself, whenever it appears during the entire cycling lifespan; however, discussion on this issue is rare. A periodically conductive/dielectric lamella scaffold is developed for hosting Li metal to realize a "self-correction" functionality, which can automatically synchronize Li deposition/stripping by periodically re-homogenizing electric field distribution around irregular Li protrusions. Consequently, dendrite-free Li plating/stripping with high Coulombic efficiency can be achieved even at 5 mA cm −2 and an ultrahigh cycling capacity of 15 mAh cm −2 . Notably, a maximal cumulative plating capacity of 4000 mAh cm −2 with Li utilization of 50% is realized, outperforming most recently reported results. This work provides new insights for designing future smart high-performance metal anode batteries for real application.commercialization. For decades, numerous efforts have been devoted to eliminating/ delaying Li dendrites, involving interface engineering, [4][5][6] electrolyte modification, [7][8][9] and adopting 3D lithophilic host, [10,11] etc. However, the tendency for Li-dendrite formation cannot be fully avoided during repeated Li plating/stripping process, as it is thermodynamically and kinetically favorable. [12,13] Owing to the intrinsically intricate influencing factors (e.g., Li ion concentration, local potentials, local current, temperature distributions, [14][15][16][17] and interface energy difference. [18] ), unsynchronized and irregular Li metal propagation is prone to occur in electrochemical "hotspots" during Li plating, which could trigger self-amplified parasitic and dendritic growth (Figure 1a). Although intensive fundamental studies with well-established models have explored the growth mechanism of Li dendrites, technically it is extremely difficult to predict their emergence and manage their growth, especially when batteries are cycling under high a current density and high capacity conditions. To solve the safety problem of Li metal anodes and extend their cycle life, a few strategies have been proposed, including modulating the dendrite growth directions, [12,19,20] reacting dendrites with a modified separator, [21] healing dendrites by heating, [22] and equipping battery with real-time monitoring systems,. [23,24] In particular, compositing Li metal with 3D hosts has been demonstrated as a promising solution to stabilize Li metal plating at high working current density and high capacity. [25] Specifically, employing an...

Super Electrolyte-Philic Boron Nitride Nanotube Membranes as Highly Robust Separators for Lithium Batteries

“…As compared with results across the published reports, the devices with the BNNTMs separator exhibit excellent Li dendritesuppressing ability to enable exceptional small overpotential ( Supplementary Fig. 13) and cycling stability with a cumulative lifetime capacity exceeding 4,000 mAh cm -2 , exceeding the lifetime capacity of typical LIBs (typically < 2,000 mAh cm -2 ) 44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60 (Fig. 4j) (Details are shown in Supplementary Table S3).…”

Carbon-containing electrospun nanofibers for lithium–sulfur battery: Current status and future directions

“…Therefore, Li, when uniformly coated on the surface of the porous CENFs with high SSA, exhibits better interface stability than Li foils in the plating/stripping process. Whether the porous CENFs are carbonized by heat treatment or directly surface-modified, or are instead combined with polymerbased nanofibers to form the periodic polymer/CENFs host [132], the improvement in the Li wettability and the construction of a lithophilic surface layer by lithophilic nanoparticles or functional groups are always indispensable.…”

Dendrite‐free lithium and sodium metal anodes with deep plating/stripping properties for lithium and sodium batteries

“…Besides offering shortcuts for ions' diffusion, the pores in 3D porous frameworks can also act as the void buffer for metal deposit, relaxing the internal stress fluctuation caused by the volume change during Li or Na plating/stripping. Therefore, the metal anodes constructed by 3D porous frameworks could achieve stable cycling performance at moderate current densities (<3 mA cm −2 ) and areal capacities (<3 mAh cm −2 ) 6,7,9–14 . However, realizing dendrite‐free metal plating/stripping under high current densities (>5 mA cm −2 ) and high areal capacities (>5 mAh cm −2 ) still remains a large challenge for alkali metal anodes.…”