Ultrahigh‐Energy‐Density Flexible Lithium‐Metal Full Cells based on Conductive Fibrous Skeletons

Abstract

Despite extensive studies on lithium‐metal batteries (LMBs) that have garnered considerable attention as a promising high‐energy‐density system beyond current state‐of‐the‐art lithium‐ion batteries, their application to flexible power sources is staggering due to the difficulty in simultaneously achieving electrochemical sustainability and mechanical deformability. To address this issue, herein, a new electrode architecture strategy based on conductive fibrous skeletons (CFS) is proposed. Lithium is impregnated into nickel/copper‐deposited conductive poly(ethylene terephthalate) nonwovens via electrochemical plating, resulting in self‐standing CFS–Li anodes. The CFS–Li anodes exhibit stable Li plating/stripping cyclability and mechanical deformability. To achieve high‐capacity flexible cathodes, over‐lithiated layered oxide (OLO) particles are compactly embedded in conductive heteronanomats (fibrous mixtures of multiwalled carbon nanotubes and functional polymer nanofibers). The conductive heteronanomats, as CFS of OLO cathodes, provide bicontinuous electron/ion conduction pathways without heavy metallic current collectors and chelate metal ions dissolved from OLO, thus improving the areal capacity, redox kinetics, and cycling retention. Driven by the attractive characteristics of the CFS–Li anodes and CFS–OLO cathodes, the resulting CFS–LMB full cells provide improvements in the cyclability, rate performance, and more notably, (cell‐based) gravimetric/volumetric energy density (506 Wh kgcell−1/765 Wh Lcell−1) along with the exceptional mechanical flexibility.

Lithiophilic Interphase Porous Buffer Layer toward Uniform Nucleation in Lithium Metal Anodes

“…This is similar to the previously reported bare Cu electrode deposition behavior. [47] When the Li metal is stripped from the Cu, petal-shaped dead Li remains on the electrode owing to the highest diffusion barrier of Li (Figure 6b4 and Figure S15, Supporting Information), symbolizing serious spoilage of Cu current collector, low Li utilization, and deterioration of corresponding battery performance. The cross-section SEM images of various anode are also revealed (the thickness of Cu foil and modified material layer is 8 and 10 µm, respectively).…”

In Situ Construction of Efficient Interface Layer with Lithiophilic Nanoseeds toward Dendrite‐Free and Low N/P Ratio Li Metal Batteries

“…Figure 5b summarizes the electrochemical performance comparison of CC@Sb 2 S 3 @Li anode with the reported literature at 5 mA cm −2 applying the ether‐based electrolyte. [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ] As exhibited, the performance of CC@Sb 2 S 3 @Li far exceeds the published works in terms of its ultralong cycle life (≈3200 cycles) and small polarization voltage (≈18 mV). In addition, the results achieved in the recently reported literature on the construction of 3D structured Li anode are cited (Table S1 , Supporting Information), and the comparative results show that the method used in this study demonstrates excellent advantages in terms of both cycle life and polarization voltage.…”

Covalent Organic Frameworks and Their Derivatives for Better Metal Anodes in Rechargeable Batteries

“…39,40 Sixth, Li metal anode exhibits a certain plasticity and can be processed into various shapes, which extends its application in flexible LIBs. 41,42 Issues of Li Metal Anodes. Li metal anode has been studied for more than 40 years.…”

“…First, the theoretical specific capacity of Li metal anode is 3860 mAh g –1 , nearly 10 times larger than that of graphite anode (372 mAh g –1 ). , Second, the electrochemical potential of Li metal is −3.04 V ( vs standard hydrogen electrode, SHE), which is much lower than other metal anodes (Na, K, Zn, Ca, Mg, Fe, Al, etc . ). − Third, Li metal anode is lightweight (0.53 g cm –3 ), which is able to boost the energy density of LIBs. , Fourth, unlike other high-capacity anodes (such as Si, SiO, and Sn), Li metal anode owns the ability to directly pair with Li-free high-capacity cathode (such as V 2 O 5 , O 2 , S, and Se) to construct next-generation high-energy-density LIBs. , Fifth, Li metal anode has a superior electronic conductivity, which could accelerate the transfer of electrons in the electrochemical process, finally accelerating the electrochemical kinetics of batteries. , Sixth, Li metal anode exhibits a certain plasticity and can be processed into various shapes, which extends its application in flexible LIBs. , …”