Rationalized design of hyperbranched trans-scale graphene arrays for enduring high-energy lithium metal batteries

Abstract

Lithium (Li) metal anode have shown exceptional potential for high-energy batteries. However, practical cell-level energy density of Li metal batteries is usually limited by the low areal capacity (<3 mAh cm −2 ) because of the accelerated degradation of high–areal capacity Li metal anodes upon cycling. Here, we report the design of hyperbranched vertical arrays of defective graphene for enduring deep Li cycling at practical levels of areal capacity (>6 mAh cm −2 ). Such atomic-to-macroscopic trans-scale design is rationalized by quantifying the degradation dynamics of Li metal anodes. High-energy Li metal cells are prototyped under realistic conditions with high cathode capacity (>4 mAh cm −2 ), low negative-to-positive electrode capacity ratio (1:1), and low electrolyte-to-capacity ratio (5 g Ah −1 ), which shed light on a promising move toward practical Li metal batteries.

An ultralight, pulverization-free integrated anode toward lithium-less lithium metal batteries

“…To highlight the superiority of our results compared with recently published work, we summarize and compare the full-cell performance at both the cell level and anode level. Figure S22 and table S3 give the comparison of our integrated anode with recently reported lithium metal anodes (11,19,25,26,35,(41)(42)(43)(44)(45)(46), in terms of total-anode specific capacity (calculated by dividing the areal capacity by the total anode mass) and cycling performance in a full cell. Our integrated anode demonstrates superior comprehensive performance in total anode specific capacity and fullcell cycling.…”

“…In a practical battery, the positive/negative electrodes (including the collector) account for approximately 70 wt % of the total mass of the battery. Increasing the amount of extractable lithium per mass unit in the active material or minimizing the proportion of inactive material (e.g., collector) at the electrode level can enhance the energy density of the battery (14)(15)(16)(17)(18)(19)(20). On the cathode side, the theoretical capacity of layered Li-rich materials is approaching their upper limit due to the limitations of topochemical Li + intercalation chemistry (21)(22)(23)(24).…”

LiF-Rich Interfacial Protective Layer Enables Air-Stable Lithium Metal Anodes for Dendrite-Free Lithium Metal Batteries

“…Recently, the exponential rise in demands for vehicle electrification, device automation, and renewable energy harvesting has led to intensified research studies in high-energy-density batteries. Lithium metal batteries (LMBs), particularly lithium–sulfur and lithium–oxygen batteries, are deemed as promising candidates, attributing to the ultra-high theoretical capacity (3860 mA h g –1 ) and the lowest electrochemical potential (−3.04 V vs standard hydrogen electrode) of lithium (Li) metal anodes. − However, the implementation of Li metal anodes is hampered by numerous challenges, including Li dendrite growth, − “dead Li”, − uncontrollable volume change, − and unstable solid electrolyte interphase (SEI). − Upon contact with an electrolyte, Li metal reacts spontaneously and generates a SEI layer on the surface, which is unstable and easily destroyed during cycling . Subsequently, dendritic Li tends to grow through the cracks of the SEI, causing battery short circuit.…”

Ultra‐Sleek High Entropy Alloy Tights: Realizing Superior Cyclability for Anode‐Free Battery

“…[ 10–13 ] In order to improve the ability of cathode materials to store Li‐ions, currently reported LIBs generally use excessive lithium metal as the anodes. [ 14–17 ] However, Li anodes with high Li content can cause low Li utilization (typically < 10%) and eventually degrade the energy density of the whole LIB device. [ 18–20 ]…”

“…[10][11][12][13] In order to improve the ability of cathode materials to store Li-ions, currently reported LIBs generally use excessive lithium metal as the anodes. [14][15][16][17] However, Li anodes with high Li content can cause low Li utilization (typically < 10%) and eventually degrade the energy density of the whole LIB device. [18][19][20] Recently, anode-free battery architecture completely eliminates the excess of active Li by pairing only Li-rich cathodes with a bare metal current collector, thereby endowing the full cell with the highest specific energy and energy density.…”