Long‐Life, High‐Rate Lithium–Sulfur Cells with a Carbon‐Free VN Host as an Efficient Polysulfide Adsorbent and Lithium Dendrite Inhibitor

Abstract

Lithium–sulfur (Li‐S) batteries are a promising next‐generation energy‐storage system, but the polysulfide shuttle and dendritic Li growth seriously hinder their commercial viability. Most of the previous studies have focused on only one of these two issues at a time. To address both the issues simultaneously, presented here is a highly conductive, noncarbon, 3D vanadium nitride (VN) nanowire array as an efficient host for both sulfur cathodes and lithium‐metal anodes. With fast electron and ion transport and high porosity and surface area, VN traps the soluble polysulfides, promotes the redox kinetics of sulfur cathodes, facilitates uniform nucleation/growth of lithium metal, and inhibits lithium dendrite growth at an unprecedented high current density of 10 mA cm−2 over 200 h of repeated plating/stripping. As a result, VN‐Li||VN‐S full cells constructed with VN as both an anode and cathode host with a negative to positive electrode capacity ratio of only ≈2 deliver remarkable electrochemical performance with a high Coulombic efficiency of ≈99.6% over 850 cycles at a high 4 C rate and a high areal capacity of 4.6 mA h cm−2. The strategy presented here offers a viable approach to realize high‐energy‐density, safe Li‐metal‐based batteries.

Dual‐Functional Atomic Zinc Decorated Hollow Carbon Nanoreactors for Kinetically Accelerated Polysulfides Conversion and Dendrite Free Lithium Sulfur Batteries

“…Moreover, the self-discharge phenomenon is also efficiently suppressed by using these two advanced electrodes with a stable open circuit voltage (2.4 V) for 45 h ( Figure S28, Supporting Information). More importantly, the obtained Li-S full battery shows superior rate performance with a highly reversible capacity of 989 mAh g −1 and high CE ≈ 100% at an ultrahigh rate of 10 C. Remarkably, the ultrahigh rate performance has rarely reported in the former work, such as VN-S (910 mAh g −1 at 4 C), [30] graphene-S (713 mAh g −1 at 10 C), [31] illustrating the fast reaction kinetics (Figure 5c; Figure S29, Supporting Information). The maximum specific power density (13 325 W kg −1 ) and energy density (1793 Wh kg −1 ) calculated based on the mass of Zn 1 -HNC-S cathode is competitive to most previous reports ( Figure S30, Supporting Information), such as graphene-S (2095 W kg −1 , 1308 Wh kg −1 ), [31] graphite foam-S (9583 W kg −1 , 1613 Wh kg −1 ), [32] and cobalt in nitrogen-doped graphene-S (3540 W kg −1 , 1715Wh kg −1 ).…”

Strategies toward High‐Loading Lithium–Sulfur Battery

“…[59,60] For the polar host materials, sufficient electronic conductivity is necessary to ensure effective sulfur utilization in high-loading sulfur electrodes. [61] If the strong absorbents were non-conductive, the absorbed LiPS could not receive electrons availably, thus preventing the electrochemical redox processes. In this case, the adsorbed LiPSs have to travel to the surface of the conducive host, which will slow down the reaction rate.…”

Advances in the Design of 3D‐Structured Electrode Materials for Lithium‐Metal Anodes

“…Therefore, high-aspect-ratio metal nanowires were assembled as a self-supported 3D network structure to substitute the typical current collectors (Figure 2e,f). [65][66][67][68][69] The nanostructured host electrode materials can provide a well-developed conducting network structure and numerous macropores for Li metal storage as well as a high open surface area with active catalytic sites. In addition, such materials can exhibit high flexibility, as shown in Figure 2f) for a freestanding 3D Cu nanowire network.…”

“…In addition, such materials can exhibit high flexibility, as shown in Figure 2f) for a freestanding 3D Cu nanowire network. [67] In a continuous metal plating/dissolution process conducted for 200 cycles (200 h), several self-supported electrode materials such as Ni@Li 2 O co-axial nanowires, [65] free-standing Cu nanowire networks, [66] phosphidized 3D Cu nanowire networks, [67] and 3D vanadium nitride (VN) nanowire arrays [68] showed high CEs of 97.3-99.9% and stable cycling behavior without dendritic metal growth.…”