Methods to Improve Lithium Metal Anode for Li-S Batteries

Abstract

The lithium-sulfur (Li-S) battery has received a lot of attention because it is characterized by high theoretical energy density (2,600 Wh/kg) and low cost. Though many works on the "shuttle effect" of polysulfide have been investigated, lithium metal anode is a more challenging problem, which leads to a short life, low coulombic efficiency, and safety issues related to dendrites. As a result, the amelioration of lithium metal anode is an important means to improve the performance of lithium sulfur battery. In this paper, improvement methods on lithium metal anode for lithium sulfur batteries, including adding electrolyte additives, using solid, and/or gel polymer electrolyte, modifying separators, applying a protective coating, and providing host materials for lithium deposition, are mainly reviewed. In addition, some challenging problems, and further promising directions are also pointed out for future research and development of lithium metal for Li-S batteries.

Covalent Assembly of Two‐Dimensional COF‐on‐MXene Heterostructures Enables Fast Charging Lithium Hosts

“…According to Sand's law, a 3D conductive host can facilitate mass transfer, reduce local current density, and prevent charge accumulation. [40][41][42] Moreover, lithiophilic, ordered channels at the electrode/electrolyte interface are crucial for uniform Li + diffusion and reduced nucleation overpotentials, which enables Li growth throughout the entire framework instead of on a single tip or edge. [41,43,44] When employing the prepared MXene@COF framework as Li plating host, we envisage that it meets these key properties necessary for dendrite-free regulation.…”

Strategies to anode protection in lithium metal battery: A review

“…Novel 3D porous current collector scaffolds for Li‐based battery technology in particular are receiving considerable attention due to its low impact on battery performance and matching requirements to other battery components. The skeleton of a 3D current collector inhibits the dendritic Li growth in two main ways: (i) large surface‐to‐volume ratio increases interaction time of Li ions with collector thereby consuming Li ions which may form dendrites and (ii) normalizes Li ion flux through the collector thereby improving uniformity of Li plating or stripping on lithophilic sites 15,84‐86 . In addition, the 3D porous current collector is acts as a stable Li host material.…”

A closed-host bi-layer dense/porous solid electrolyte interphase for enhanced lithium-metal anode stability

“…Part of this transitional effort is focused on energy storage via a rechargeable battery. Lithium metal is often considered the "Holy Grail" of rechargeable battery technology, due to its high theoretical capacity (3,860 mAh/g) and low electrochemical potential (À3.04 V vs. SHE), which has the practical capability of achieving a specific energy above 500 Wh/kg when paired with a high-theoretical capacity sulfur or high-voltage Ni-rich LiNi 1ÀyÀz Mn y Co z O 2 (NMC) cathode [1][2][3][4][5][6][7][8].…”

“…The variability in crystalline grain distribution has a severe impact on ionic flux distribution [16]. Others have shown that additives such as LiNO 3 improve the cyclability of Li||S batteries by forming a stabilized SEI, in addition to lessening the polysulfide shuttling effect [3,4,18,19]. An electrolyte with salt aggregation and limited solvation to Li + , such as high-concentration electrolytes (HCE) and localized high-concentration electrolytes (LHCE), can increase the salt's reduction potential and render a salt-reduced SEI layer (e.g., inorganic LiF-rich) rather than a solvent-reduced SEI layer (e.g., mixed organic-inorganic) [20][21][22][23].…”