An Azamacrocyclic Ligand-Functionalized Transition-Metal Scavenging Polymer for 5.0 V Class High-Energy Lithium-Ion Batteries

Abstract

The electrochemical performance of 5.0 V class full cells comprising LiNi 0.5 Mn 1.5 O 4 -graphite is improved by applying metal scavenging coats on the negative electrode surface. To achieve this transition-metal scavenging ability, a tetradentate azamacrocyclic ligand is introduced into a poly(vinyl alcohol) (PVA) backbone through a one-step esterification reaction. The azamacrocyclic ligand-functionalized PVA scavenged five times as many metal ions as that of the pristine polymer counterpart. Due to this scavenging ability, the Coulombic efficiency and cyclability are greatly enhanced in a LiNi 0.5 Mn 1.5 O 4 /functionalized graphite cell composition. Consequently, the increase in discharge resistance during cycles was well retained due to the introduction of this functional polymer on the negative electrode surface.

Solution NMR of Battery Electrolytes: Assessing and Mitigating Spectral Broadening Caused by Transition Metal Dissolution

“…We also note that compounds other than Li 3 PO 4 may be used to complex or chelate dissolved Mn 2+ and reduce its effect on NMR spectra without causing HF consumption. The Mn-chelating abilities of various compounds (typically polymers) have been explored in electrolyte solutions with an aim toward reducing metal dissolution and deposition ,− and may be suitable for use in mitigating peak broadening, as long as 1 H signals from the chelating agent do not overlap with 1 H signals of interest.…”

Stable Li Metal–Electrolyte Interface Enabled by SEI Improvement and Cation Shield Functionality of the Azamacrocyclic Ligand in Carbonate Electrolytes

“…Furthermore, the energy generated by the formation of a Li-chelating complex might negatively shift the plating potential of the Li-ion, implying the possibility of cationic shielding of the Li metal electrode. The nitrogen-based ligand has better metal-ion binding ability than the typical oxygen-based ligand and thus can outperform previously reported ligand-based additives. − The self-healing electrostatic shield mechanism is used as a mitigation strategy to enhance the reversibility of the Li electrode in carbonate electrolytes because the Li metal morphology is regulated by the shielding of negative charge-accumulated dendritic Li. , However, the metal-ion source is typically cesium- and rubidium-based salts which are rare-earth elements; hence, the cost-effectiveness and availability of the metal ion as an electrolyte additive are severely constrained in practical application. Meanwhile, integrating an azamacrocyclic ligand with LiNO 3 salt can provide SEI modification via the nitrate anion as well as cation shield functionality from the electrolyte-abundant Li-ion-chelated ligand molecule, which is a rare-earth element free electrolyte with bifunctionality.…”

One-Step Synthesis of ZnNCN Nanoparticles with Adjustable Composition for an Advanced Anode in Lithium Ion Battery

“…Lithium ion batteries (LIBs) have been used widely in various electric equipment, such as cellphones, unmanned aerial vehicles, and electric vehicles. − The goal of increasing the volume/mass energy density prompts the need of development in new-type anode materials in LIBs. − Thus, the development of a novel anode with high capacity, low cost, and simple preparation method is very important. − …”