3D Carbon-Based Porous Anode with a Pore-Size Gradient for High-Performance Lithium Metal Batteries

Abstract

Three-dimensional (3D) hosts have been identified as the most promising anode design for lithium metal batteries (LMBs). This has been previously demonstrated to be extremely effective at inhibiting the dendrite growth by reducing the local current densities, resulting in stable cycle performances. However, due to the complex synthetic procedures and low lithium utilization ratios, the practical application of the 3D host anode still remains a challenge. To address these issues, the current study reports the development and synthesis of a 3D-carbon-based porous anode (3D-CPA) with a pore-size gradient using a practical slurry-based process in which the pore sizes decrease from the top to bottom layer. The pore-size gradient design accomplished using carbon materials enables stable Li plating/stripping into the entire inner pores without the formation of dendrites and also confirms the high energy density of LMB. The as-prepared 3D-CPA with a pore-size gradient also demonstrated a higher average coulombic efficiency of 98.8% (250 cycles) than other 3D-CPAs with mono-pore sizes. Additionally, its symmetry cell had a prolonged lifespan of 660 hrs at 1 mAcm–2 (Li utilization ratio = 50%) and 680 hrs at 2 mAcm–2 (Li utilization ratio = 30%). Remarkably, a pouch full cell composed of LiNi0.6Co0.2Mn0.2 (NCM622) with 4 mA h cm–2/as-prepared 3D-CPA retained 87.2% of its capacity after 100 cycles, using a carbonate-based electrolyte. The current study, therefore, highly suggests the use of 3D host designs for the fabrication of LMBs to achieve reversible Li reactions, leading to long-term stability.

Present and future of functionalized Cu current collectors for stabilizing lithium metal anodes

“…Reproduced with permission from Ref. [196], © American Chemical Society 2021. (f) Schematics of the preparation of LIGHS@Cu, and the Li deposition processes of bare Cu and LIGHS@Cu substrates.…”

“…Consequently, the MNCu/FC electrode delivers a CE of 97.9% after 150 cycles at 2 mA•cm -2 and 1 mAh•cm -2 . Noh et al prepared a 3D carbon-based porous architecture covered Cu substrate (3D CPA) by blade casting, where graphite, polyamideimide, and PMMA were used the frame material, binder, and pore template agents, respectively [196]. As shown in Fig.…”

“…SEM images of 3D-CPA (b, c) with 4 mAh•cm -2 Li plating and(d, e) after Li stripping. Reproduced with permission from Ref [196],. © American Chemical Society 2021.…”

Columnar Lithium Deposition Guided by Graphdiyne Nanowalls toward a Stable Lithium Metal Anode

“…For example, a two-dimensional (2D) Cu substrate modified with a hollow carbon nanosphere layer, a hollow semigraphitic carbon-coated SiO x /C microsphere layer, and a three-dimensional (3D) Ni skeleton coated with onion-like carbon granules allowed for stable Li metal anodes. Furthermore, 3D porous carbon-based materials , and 3D frameworks formed by carbon fibers − were prepared as 3D current collectors to stabilize Li metal anodes. Interestingly, a variety of carbon nanomaterials including carbon nanotubes − and graphene − were successfully used for fabricating stable Li metal anodes.…”

One-Dimensional Porous Li-Confinable Hosts for High-Rate and Stable Li-Metal Batteries

“…Metallic lithium (Li) has attracted increasing attention as a promising next-generation anode material owing to its attractive properties, such as high theoretical capacity (3860 mAh g –1 ) and low operating potential (−3.04 V vs standard hydrogen electrode). − However, poor Coulombic efficiency (CE) and catastrophic safety issues, mainly originating from the undesirable dendritic Li growth, have impeded its practical applications. To overcome these inherent shortcomings, considerable efforts have been devoted to realizing Li anodes in Li-metal batteries, including the development of three-dimensional (3D) conductive hosts, − functional electrolytes, − protection layers, − and solid electrolytes. − Among them, the 3D structures consisting of Cu nanowires or carbon materials such as graphite, graphene, and carbon nanotubes can reduce the effective current density and store metallic Li in the inner space of the host; the Li dendrite growth and drastic volume expansion during cycling can be largely mitigated in the 3D Li host. ,,, However, despite these advantages, internal short circuits can take place by the preferential Li deposition on the top surface of the structure (i.e., top plating) due to its conductive nature, eventually hindering the use of the bottom region of the host as Li storage space.…”