Frontiers in Batteries and Electrochemistry最新文献

{"title":"Interfacial pressure improves calendar aging of lithium metal anodes","authors":"Kimberly L. Bassett, Kathryn A. Small, Daniel M. Long, Laura C. Merrill, Benjamin Warren, Katharine L. Harrison","doi":"10.3389/fbael.2023.1292639","DOIUrl":"https://doi.org/10.3389/fbael.2023.1292639","url":null,"abstract":"Lithium (Li) metal is a promising anode because its theoretical specific capacity is approximately ten times larger than graphite. However, Li anodes suffer from long-term capacity fade due to Li stranding (becoming electronically disconnected) and electrolyte decomposition. Applied interfacial pressure has been shown to improve Li anode cycling, likely due to reincorporating stranded or “dead” Li into the anode. Calendar aging can also lead to Li capacity loss due to electrolyte decomposition/Li corrosion and the formation of stranded Li. Some research suggests that calendar aging during cycling results in reversible capacity losses due to Li stranding and reconnection. We here investigate the effect of applied interfacial pressure on Li anode calendar aging during cycling with incorporated rest steps in a localized high-concentration electrolyte (LHCE) to understand if pressure can mitigate stranded Li formation during rest by manipulating the Li morphology. Pouch cells exhibit more stable cycling and denser Li deposits between 10 kPa and 1,000 kPa of applied pressure compared to no applied pressure. Despite drops in CE during periodic rest cycles, the average cumulative lost capacity and average coulombic efficiency (CE) of cells over 50 cycles show that cells aged with incorporated rest steps perform similarly to cells cycled without added rests. This similar average CE suggests that dead Li is largely responsible for drops in CE during rest rather than irreversible Li corrosion and that the dead Li can be reconnected in subsequent cycling. The addition of a lithiophilic ZnO coating to the Cu working electrode increases the adhesion and coverage of Li deposits at low pressures and improves CE during the first cycle.","PeriodicalId":474803,"journal":{"name":"Frontiers in Batteries and Electrochemistry","volume":"2020 44","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135814191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into the reactivity and lithium plating mechanisms of ultra-thin metal oxide coatings for anode-free solid-state lithium metal batteries","authors":"Michael J. Counihan, Taewoo Kim, Rajesh Pathak, Teodora Zagorac, Yingjie Yang, Meghan E. Burns, Jordi Cabana, Robert F. Klie, Luke Hanley, Justin G. Connell, Anil U. Mane, Jeffrey W. Elam, Sanja Tepavcevic","doi":"10.3389/fbael.2023.1292622","DOIUrl":"https://doi.org/10.3389/fbael.2023.1292622","url":null,"abstract":"Solid-state batteries (SSBs) in an “anode-free” cell format using lithium metal anodes are the best candidates for high energy density battery applications. However, low lithium metal Coulombic efficiency and charge loss due to solid electrolyte interphase (SEI) formation severely limit the cycle life of anode-free SSBs. Here, we explore ultra-thin (5–20 nm) Al 2 O 3 and ZnO coatings deposited by atomic layer deposition (ALD) on copper electrodes for anode-free cells with a solid polymer electrolyte. Voltammetry shows that lithium inventory loss from SEI formation is reduced over 50% with Al 2 O 3 @Cu electrodes, but these electrodes experience orders of magnitude higher interface resistances than bare Cu and ZnO@Cu electrodes due to low ionic and electronic conductivities. The electrochemical differences are reflected in XPS, where Al 2 O 3 undergoes a self-limiting lithiation reaction with Li 0 , while ZnO reacts completely with Li 0 to form LiZn and Li 2 O. These chemical differences result in higher and lower lithium plating nucleation overpotentials for Al 2 O 3 (up to 220 mV) and ZnO (down to 15 mV) coatings, respectively, relative to uncoated Cu electrodes (35 mV). ToF-SIMS reveals lithium plating underneath a Li y AlO x coating and through emergent defects and pinholes with Al 2 O 3 @Cu electrodes, while it plates exclusively on top of converted ZnO@Cu electrodes. SEM corroborates these mechanisms, showing sparse coverage of isolated Li clusters plated with Al 2 O 3 @Cu electrodes, while Cu and ZnO@Cu grow more dense and interconnected deposits. Despite both coatings improving different aspects of anode-free battery design, unmodified Cu electrodes show higher Coulombic efficiencies (∼77%) than Al 2 O 3 @Cu (up to 70%) and ZnO@Cu (up to 75%) electrodes. Increasing Al 2 O 3 thickness decreases the practical current density compared to unmodified Cu (30 µA/cm 2 ), but increasing ZnO thicknesses can double or triple this value. These (electro)chemical and morphological observations suggest two mechanisms: less-reactive metal oxides develop lithium ion conductivity through their structure to plate lithium underneath, while more-reactive metal oxides undergo full reduction and conversion with lithium plating above the coating. This fundamental research opens future work to leverage these mechanisms and explore other materials for high-efficiency anode-free SSBs.","PeriodicalId":474803,"journal":{"name":"Frontiers in Batteries and Electrochemistry","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136067557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reasonable design of thick electrodes in lithium-ion batteries","authors":"Yoon Bo Sim, Bo Keun Park, Ki Jae Kim","doi":"10.3389/fbael.2023.1272439","DOIUrl":"https://doi.org/10.3389/fbael.2023.1272439","url":null,"abstract":"To achieve a high energy density for Li-ion batteries (LIBs) in a limited space, thick electrodes play an important role by minimizing passive component at the unit cell level and allowing higher active material loading within the same volume. Currently, the capacity of active materials is close to the theoretical capacity; therefore, thick electrodes provide the clearest solution for the development of high-energy-density batteries. However, further research is needed to resolve the electrochemical and mechanical instabilities inside the electrode owing to its increased thickness. This review summarizes the various methods and recent research aimed at fabricating electrodes with low-torsion and uniform pore structure for fast ion transport, based on an in-depth consideration of the challenges encountered in thick electrodes. In addition, future developments and research directions necessary to apply these methods to the industry are presented. This review will be a valuable milestone for manufacturing robust thick electrodes with high performance and for realizing ultrahigh-capacity/density batteries in the future.","PeriodicalId":474803,"journal":{"name":"Frontiers in Batteries and Electrochemistry","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135246616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}