Roll‐To‐Roll Fabrication of Zero‐Volume‐Expansion Lithium‐Composite Anodes to Realize High‐Energy‐Density Flexible and Stable Lithium‐Metal Batteries

Abstract

The lithium (Li)‐metal anode offers a promising solution for high‐energy‐density lithium‐metal batteries (LMBs). However, the significant volume expansion of the Li metal during charging results in poor cycling stability as a result of the dendritic deposition and broken solid electrolyte interphase. Herein, a facile one‐step roll‐to‐roll fabrication of a zero‐volume‐expansion Li‐metal‐composite anode (zeroVE‐Li) is proposed to realize high‐energy‐density LMBs with outstanding electrochemical and mechanical stability. The zeroVE‐Li possesses a sandwich‐like trilayer structure, which consists of an upper electron‐insulating layer and a bottom lithiophilic layer that synergistically guides the Li deposition from the bottom up, and a middle porous layer that eliminates volume expansion. This sandwich structure eliminates dendrite formation, prevents volume change during cycling, and provides outstanding flexibility to the Li‐metal anode even at a practical areal capacity over 3.0 mAh cm−2. Pairing zeroVE‐Li with a commercial NMC811 or LCO cathode, flexible LMBs that offer a record‐breaking figure of merit (FOM, 45.6), large whole‐cell energy density (375 Wh L−1, based on the volume of the anode, separator, cathode, and package), high‐capacity retention (> 99.8% per cycle), and remarkable mechanical robustness under practical conditions are demonstrated.

Mechano‐Electrochemically Promoting Lithium Atom Diffusion and Relieving Accumulative Stress for Deep‐Cycling Lithium Metal Anodes

“…[34] A zeroVE-Li composite anode with sandwich-like structure can enable the full battery with NCM811 cathode cycle 200 times with a capacity retention rate ≈67% under N/P ratio of 3.6 and E/C ratio 16.2 g Ah −1 . [35] The pouch cell packaged with ELMA reveals a stable repeated charge/discharge process for 20 cycles without obvious capacity fading (Figure 5e). The disassembled ELMA maintains a flat and compact surface morphology (Figure S45, Supporting Information), keeping a good agreement with those observed in the coin cells.…”

Lithium Foam for Deep Cycling Lithium Metal Batteries

“…For example, a sandwich-like composite lithium anode with porous spacer can make a full cell operate 200 cycles with a capacity retention rate ≈70% under N/P ratio of 3.6 and E/C ratio of 13.5 µL mAh −1 . [48] 3D Li/CuZn composite anode, fabricated by thermal infusing Li into CuZn alloy host, can enable the full battery with NCM811 cathode cycle 500 times under N/P ratio of 7.5 and E/C ratio 133 µL mAh −1 . [51] The full cells using composite Li anode, consisting of Ag nanoparticle-embedded carbon macroporous fibers, have exhibited a cycle life of 250 cycles under N/P ratio of 8.8 and E/C ratio of 74 µL mAh −1 with LiFePO 4 cathode.…”

Advanced Composite Lithium Metal Anodes with 3D Frameworks: Preloading Strategies, Interfacial Optimization, and Perspectives

“…Prompted by the introduced methods in electrodeposition (Section 2.3), the pressed 3D framework can also be analogously chemically treated to enhance the surface SEI property during Li nucleation. [55,[223][224][225] For example, Xu et al designed a functionalized grid-based Li (FGLi) composite anode through mechanical pressing the Li foil with the phosphorized copper mesh (Cu@ Cu 3 P), as shown in Figure 13A. [55] The Cu@Cu 3 P mesh with the grid structure possessed a wide lithiophilic active surface, endowing a zoning effect and reduced nucleation barrier for deposited Li storage (Figure 13B), which ensured a uniform Li nucleation behavior and mitigated volume change for electrochemical cycling.…”