Interlayered Dendrite‐Free Lithium Plating for High‐Performance Lithium‐Metal Batteries

Liu

et al. 2020

Adv Funct Materials

Li metal is one of the most promising anode materials for high energy density batteries. However, uncontrollable Li dendrite growth and infinite volume change during the charge/discharge process lead to safety issues and capacity decay. Herein, a carbonized metal–organic framework (MOF) nanorod arrays modified carbon cloth (NRA‐CC) is developed for uniform Li plating/stripping. The carbonized MOF NRAs effectively convert the CC from lithiophobic to lithiophilic, decreasing the polarization and ensuring homogenous Li nucleation. The 3D interconnected hierarchal CC provides adequate Li nucleation sites for reducing the local current density to avoid Li dendrite growth, and broadens internal space for buffering the volume change during Li plating/stripping. These characteristics afford a stable cycling of the NRA‐CC electrode with ultrahigh Coulombic efficiencies of 96.7% after 1000 h cycling at 2 mA cm−2 and a prolonged lifespan of 200 h in the symmetrical cell under ultrahigh areal capacity (12 mAh cm−2) and current (12 mA cm−2). The solid‐state batteries assembled with the composite Li anode, high‐voltage cathode (LiNi0.5Co0.2Mn0.3O2), and composite solid‐state electrolyte also deliver excellent cyclic and rate performance at 25 °C. This work sheds fresh insights on the design principles of a dendrite‐free Li metal anode for safe solid‐state Li metal batteries.

Section: Resultsmentioning

confidence: 93%

High Areal Capacity Dendrite‐Free Li Anode Enabled by Metal–Organic Framework‐Derived Nanorod Array Modified Carbon Cloth for Solid State Li Metal Batteries

Liu

et al. 2020

Adv Funct Materials

“…[24] CNT scaffolds delivered an average Coulombic efficiency of ~80% during the cycling process, which could be ascribed to the high specific surface area of the conductive CNT scaffold that significantly reduces local current density. [25] However, the cell using CNT scaffolds still suffers from limited cycling life with Coulombic efficiency dropping dramatically beyond 80 cycles. Noticeably, DN-MXene/CNT scaffolds can achieve improved Coulombic efficiency (~93.1%) and cycling stability (120 cycles), which is also higher than that of N-free MXene/CNT scaffold ( Figure S12b electrolyte.…”

Section: Density Functional Theory (Dft) Calculations and Characterizmentioning

confidence: 99%

MXene‐Based Dendrite‐Free Potassium Metal Batteries

et al. 2019

Potassium metal batteries are considered as attractive alternatives beyond lithium-ion batteries. However, the uncontrollable dendrite growth on the potassium metal anode has restrained their practical applications. Herein, we report a high-performance potassium anode achieved by confining potassium metal into a titanium-deficient nitrogen-containing MXene/carbon nanotube free-standing scaffold. The high electronic transport and fast potassium diffusion in this scaffold enable reduced local current density and homogeneous ionic flux during plating/stripping process. Furthermore, as verified by theoretical calculations and experimental investigations, such "potassium-philic" MXene sheets can induce the nucleation of potassium, and guide potassium to uniformly distribute in the scaffold upon cycling. Consequently, the as-developed potassium metal anodes exhibit a dendrite-free morphology with high Coulombic efficiency and long cycle life during plating/stripping process. Such anodes also deliver significantly improved electrochemical performances in potassium-sulfur batteries compared with bare potassium metal anodes. This work can provide a new avenue for developing potassium metal-based batteries. Received: ((will be filled in by the editorial staff)) Revised: ((will be filled in by the editorial staff))

“…A stable Li metal anode is a key point for the practical application of Li metal battery (LMB) (Cheng et al, 2017;Lu et al, 2014;Qiao et al, 2017;Zhang et al, 2018). Therefore, explorations on non-dendrite anode and reducing dead Li are eagerly required, such as high-modulus SEI film coating on Li metal (Liu et al, 2019a;Shi et al, 2018;Wang et al, 2017b), high-surface-energy substrate (Hou et al, 2019;Wang et al, 2017a), low local current density (Zhang et al, 2017), more reaction sites , cross-linking film (Zhao et al, 2019), and so on (Liang et al, 2019;Westover et al, 2019;Xu et al, 2019). However, once the uncontrollable dendrite occurs, the negative feedback cycle (SEI broken, dendrite worsen and so on) that follows would cause Li metal anode's failure quickly.…”

Section: Introductionmentioning

confidence: 99%

Synchronous Healing of Li Metal Anode via Asymmetrical Bidirectional Current

Qin

et al. 2020

iScience

The creation of Li metal anodes while minimizing dendrite growth is an important challenge for developing high-energy density batteries. Dendrites can originate from an inhomogeneous charge distribution or an irregular substrate, and often, the way to suppress dendrite growth is to avoid their formation altogether (ion-uniform mechanism over a shelf time). Herein, we propose a different route to eliminate dendrite formation, called an asymmetrical bidirectional current mode (ABCM) of charging, leading to a healable Li metal anode and resulting in a positive feedback cycle. This mode allows for a stable cyclic performance and suppresses dendrite formation effectively (while holding the polarization $27 mV for over 1,000 h), and provides a better result than suppressing Li dendrites via weakening of the Li dendrite (ion-uniform mechanism). These results indicate that ABCM may be a promising way to stabilize the Li anode of Li metal batteries, without any chemical/physical modification of the anode.