Modification of Cu Current Collectors for Lithium Metal Batteries – A Review

The most commonly used zinc foil anode for aqueous zinc‐ion batteries suffers from poor cycle stability and low zinc utilization. Zinc‐plated anodes on the host materials with high zincophilicity and stability are receiving increasing attention to alleviate these above issues. Here, the high zinc deposition activity of Cu (2 2 0) is confirmed through experimental observations and theoretical calculations and then Cu (2 2 0) substrates are prepared with the highly preferred orientation through an industrial electrolysis strategy. The prepared Cu (2 2 0) substrate can consistently modulate dense zinc growth by inducing the Zn (0 0 1) growth with the lowest surface energy and exposing high‐index zinc facets due to its exceptional grain size, high deposition activity, and homogeneous crystal orientation, which result in the high zinc plating/stripping reversibility of this Cu (2 2 0) substrate. When assembled into the Zn//MnO2 battery, the zinc‐plated Cu (2 2 0) can deliver capacity retention of 93.9% after 640 cycles at high zinc utilization (≈20%). This scalable orientation design strategy provides a new perspective for realizing dendrite‐free metal deposition with special textures.

High‐Index Zinc Facet Exposure Induced by Preferentially Orientated Substrate for Dendrite‐Free Zinc Anode

Alkali metals (i.e., Li, Na, and K) are promising anode materials for next‐generation high‐energy‐density batteries due to their superior theoretical specific capacities and low electrochemical potentials. However, the uneven current and ion distribution on the anode surface probably induces undesirable dendrite growth, which leads to significant safety hazards and severely hinders the commercialization of alkali metal anodes. A smart and versatile strategy that can accommodate alkali metals into porous metal current collectors (PMCCs) has been well established to resolve the issues as well as to promote the practical applications of alkali metal anodes. Moreover, the proposal of PMCCs can meet the requirement of the dendrite‐free battery fabrication industry, while the electrode material loading exactly needs the metal current collector component as well. Here, a systematic survey on advanced PMCCs for Li, Na, and K alkali metal anodes is presented, including their development timeline, categories, fabrication methods, and working mechanism. On this basis, some significant methodology advances to control pore structure, surface area, surface wettability, and mechanical properties are systematically summarized. Further, the existing issues and the development prospects of PMCCs to improve anode performance in alkali metal batteries are discussed.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/advs.202205695

Porous Metal Current Collectors for Alkali Metal Batteries

Building lithium metal batteries under lean electrolyte conditions: challenges and progress

The electrolyte‐wettability of electrode materials in liquid electrolytes plays a crucial role in electrochemical energy storage, conversion systems, and beyond relied on interface electrochemical process. However, most electrode materials do not have satisfactory electrolyte‐wettability for possibly electrochemical reaction. In the last 30 years, there are a lot of literature have directed at exploiting methods to improve electrolyte‐wettability of electrodes, understanding basic electrolyte‐wettability mechanisms of electrode materials, exploring the effect of electrolyte‐wettability on its electrochemical energy storage, conversion, and beyond performance. This review systematically and comprehensively evaluates the effect of electrolyte‐wettability on electrochemical energy storage performance of the electrode materials used in supercapacitors, metal ion batteries, and metal‐based batteries, electrochemical energy conversion performance of the electrode materials used in fuel cells and electrochemical water splitting systems, as well as capacitive deionization performance of the electrode materials used in capacitive deionization systems. Finally, the challenges in approaches for improving electrolyte‐wettability of electrode materials, characterization techniques of electrolyte‐wettability, as well as electrolyte‐wettability of electrode materials applied in special environment and other electrochemical systems with electrodes and liquid electrolytes, which gives future possible directions for constructing interesting electrolyte‐wettability to meet the demand of high electrochemical performance, are also discussed.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/advs.202300283

Electrolyte‐Wettability Issues and Challenges of Electrode Materials in Electrochemical Energy Storage, Energy Conversion, and Beyond

Nano-carbon-based materials are widely reported as lithium host materials in lithium metal batteries (LMBs); however, researchers report contradictory claims as to where the lithium plating occurs. Herein, the use of pure hollow core-carbon spheres coated on Cu (PHCCSs@Cu) to study the lithium deposition behavior with respect to this type of structure in lithium anode-free cells is described. It is demonstrated that the lithium showed some initial and limited intercalation into the PHCCSs and then plated on the external carbon walls and the top surface of the carbon coating during the charging process. The unfavorable deposition of lithium inside the PHCCSs is discussed from the viewpoint of lithium-ion transport and lithium nucleation. The application potential of PHCCSs and the data from these LMB studies are also discussed.

/pdf/no-evidence-of-benefits-of-host-nano-carbon-materials-for-3tqck1il.pdf

No Evidence of Benefits of Host Nano-Carbon Materials for Practical Lithium Anode-Free Cells

Here we report a novel heterostructure with ultrahigh photocatalytic performance for H2 production. The heterostructure consists of CdxZn1-xS solid solution and two dimensional Mo2C MXene. The Mo2C MXene works as...

Boosting photocatalytic performance of CdxZn1-xS for H2 production by Mo2C MXene with large interlayer distance

The formation of isolated lithium (i-Li) during cycling hinders further development of the Li-metal battery. Recent research by Liu et al. shows that i-Li is not in fact ‘dead lithium', but can be reconnected by a short period of high stripping current density at the beginning of the discharging process. 

Reconnection of isolated lithium through fast discharge

The understanding of the impedance response during the cycling process of the “anode-free” lithium metal batteries is ambiguous in the literature. Herein, we report on a combined electrochemical quartz crystal microbalance and electrochemical impedance spectroscopy study to decouple the various contributions of the impedance response of an anode-free battery. This decoupling is achieved by a comparison of the evolution of electrochemical impedance spectroscopy spectra in two- and three-electrode cells during the Li plating–stripping processes. The observed high- and medium-frequency loops of the impedance spectra can be unambiguously assigned to the charge transfer in the solid-electrolyte interface and the plated lithium layers, respectively. 

Bingxin Zhou

Papers

Modification of Cu Current Collectors for Lithium Metal Batteries – A Review

No Evidence of Benefits of Host Nano-Carbon Materials for Practical Lithium Anode-Free Cells

Boosting photocatalytic performance of CdxZn1-xS for H2 production by Mo2C MXene with large interlayer distance

Reconnection of isolated lithium through fast discharge

Decoupling of the Impedance of Solid-Electrolyte Interface and Plated Lithium: Implications for Anode-Free Lithium Metal Battery Technology