Engineering and characterization of interphases for lithium metal anodes.

Lithium metal is a very promising anode material for achieving high energy density for next generation battery systems due to its low redox potential and high theoretical specific capacity of 3860 mA h g-1. However, dendrite formation and low coulombic efficiency during cycling greatly hindered its practical applications. The formation of a stable solid electrolyte interphase (SEI) on the lithium metal anode (LMA) holds the key to resolving these problems. A lot of techniques such as electrolyte modification, electrolyte additive introduction, and artificial SEI layer coating have been developed to form a stable SEI with capability to facilitate fast Li+ transportation and to suppress Li dendrite formation and undesired side reactions. It is well accepted that the chemical and physical properties of the SEI on the LMA are closely related to the kinetics of Li+ transport across the electrolyte-electrode interface and Li deposition behavior, which in turn affect the overall performance of the cell. Unfortunately, the chemical and structural complexity of the SEI makes it the least understood component of the battery cell. Recently various advanced in situ and ex situ characterization techniques have been developed to study the SEI and the results are quite interesting. Therefore, an overview about these new findings and development of SEI engineering and characterization is quite valuable to the battery research community. In this perspective, different strategies of SEI engineering are summarized, including electrolyte modification, electrolyte additive application, and artificial SEI construction. In addition, various advanced characterization techniques for investigating the SEI formation mechanism are discussed, including in situ visualization of the lithium deposition behavior, the quantification of inactive lithium, and using X-rays, neutrons and electrons as probing beams for both imaging and spectroscopy techniques with typical examples.

Shadike Z ，Tan S ，Lin R ，Cao X ，Hu E ，Yang XQ ... -  《-》

Recent progress in SEI engineering for boosting Li metal anodes.

Wu Y ，Wang C ，Wang C ，Zhang Y ，Liu J ，Jin Y ，Wang H ，Zhang Q ... -  《-》

Correlating Solid Electrolyte Interphase Composition with Dendrite-Free and Long Life-Span Lithium Metal Batteries via Advanced Characterizations and Simulations.

Lithium metal anode attracts great attention because of its high specific capacity and low redox potential. However, the uncontrolled dendrite growth and its infinite volume expansion during cycling are extremely detrimental to the practical application. The formation of a solid electrolyte interphase (SEI) plays a decisive role in the behavior of lithium deposition/dissolution during electrochemical processing. Clarifying the essential relationship between SEI and battery performance is a priority. Research in SEI is accelerated in recent years by the use of advanced simulation tools and characterization techniques. The chemical composition and micromorphology of SEIs with various electrolytes are analyzed to clarify the effects of SEI on the Coulombic efficiency and cycle life. In this review, the recent research progress focused on the composition and structure of SEI is summarized, and various advanced characterization techniques applied to the investigation of SEI are discussed. The comparisons of the representative experimental results and theoretical models of SEI in lithium metal batteries (LMBs) are exhibited, and the underneath mechanisms of interaction between SEI and the electrochemical properties of the cell are highlighted. This work offers new insights into the development of safe LMBs with higher energy density.

Song L ，Ning D ，Chai Y ，Ma M ，Zhang G ，Wang A ，Su H ，Hao D ，Zhu M ，Zhang J ，Zhou D ，Wang J ，Li Y ... -  《-》

Catalytic Chemistry Derived Artificial Solid Electrolyte Interphase for Stable Lithium Metal Anodes Working at 20 mA cm(-2) and 20 mAh cm(-2).

A stable solid electrolyte interphase (SEI) layer is crucial for lithium metal anode (LMA) to survive in long-term cycling. However, chaotic structures and chemical inhomogeneity of natural SEI make LMA suffering from exasperating dendrite growth and severe electrode pulverization, which hinder the practical application of LMAs. Here, we design a catalyst-derived artificial SEI layer with an ordered polyamide-lithium hydroxide (PA-LiOH) bi-phase structure to modulate ion transport and enable dendrite-free Li deposition. The PA-LiOH layer can substantially suppress the volume changes of LMA during Li plating/stripping cycles, as well as alleviate the parasitic reactions between LMA and electrolyte. The optimized LMAs demonstrate excellent stability in Li plating/stripping cycles for over 1000 hours at an ultra-high current density of 20 mA cm-2 in Li||Li symmetric cells. A high coulombic efficiency up to 99.2 % in Li half cells in additive-free electrolytes is achieved even after 500 cycles at a current density of 1 mA cm-2 with a capacity of 1 mAh cm-2 .

Cheng Y ，Wang Z ，Chen J ，Chen Y ，Ke X ，Wu D ，Zhang Q ，Zhu Y ，Yang X ，Gu M ，Guo Z ，Shi Z ... -  《-》

Pre-Solid Electrolyte Interphase-Covered Li Metal Anode with Improved Electro-Chemo-Mechanical Reliability in High-Energy-Density Batteries.

Chen X ，Shang M ，Niu J 《-》