Constructing stable interfacial layers in lithium metal batteries using lithium difluoro(bisoxalato)phosphate and lithium nitrate additives

School of Energy and Chemical Engineering (Battery Science and Technology)clos

Solid Electrolyte Interphase Layers by Using Lithiophilic and Electrochemically Active Ionic Additives for Lithium Metal Anodes

The use of role-assigned ionic additives with different adsorption energies and distinct electron-accepting abilities enables the construction of a multilayer solid electrolyte interphase (SEI) with a sequential structure of lithiophilic, mechanically robust, and ion-permeable layers on Li metal anodes. The uncontrollable Li dendrite formation, which is promoted by localized electric fields on the Li metal anode, is suppressed by the lithiophilic Ag-containing inner SEI and LiF + Li3N-enriched outer SEI with reduced overpotentials upon Li deposition

Complete Genome Sequencing of Lactobacillus acidophilus 30SC, Isolated from Swine Intestine▿

Lactobacillus acidophilus 30SC has been isolated from swine intestines and considered a probiotic strain for dairy products because of its ability to assimilate cholesterol and produce bacteriocins. Here, we report the complete genome sequence of Lactobacillus acidophilus 30SC (2,078,001 bp) exhibiting strong acid resistance and enhanced bile tolerance

Cyclic Aminosilane???Based Additive Ensuring Stable Electrode???Electrolyte Interfaces in Li???Ion Batteries

Ni???rich cathodes are considered feasible candidates for high???energy???density Li???ion batteries (LIBs). However, the structural degradation of Ni???rich cathodes on the micro??? and nanoscale leads to severe capacity fading, thereby impeding their practical use in LIBs. Here, it is reported that 3???(trimethylsilyl)???2???oxazolidinone (TMS???ON) as a multifunctional additive promotes the dissociation of LiPF6, prevents the hydrolysis of ion???paired LiPF6 (which produces undesired acidic compounds including HF), and scavenges HF in the electrolyte. Further, the presence of 0.5 wt% TMS???ON helps maintain a stable solid???electrolyte interphase (SEI) at Ni???rich LiNi0.7Co0.15Mn0.15O2 (NCM) cathodes, thus mitigating the irreversible phase transformation from layered to rock???salt structures and enabling the long???term stability of the SEI at the graphite anode with low interfacial resistance. Notably, NCM/graphite full cells with TMS???ON, which exhibit an excellent discharge capacity retention of 80.4%, deliver a discharge capacity of 154.7 mAh g???1 after 400 cycles at 45 ??C

In Situ Interfacial Tuning to Obtain High-Performance Nickel-Rich Cathodes in Lithium Metal Batteries

Nickel-rich layered oxides are currently considered the most practical candidates for realizing high-energy-density lithium metal batteries (LMBs) because of their relatively high capacities. However, undesired nickel-rich cathode-electrolyte interactions hinder their applicability. Here, we report a satisfactory combination of an antioxidant fluorinated ether solvent and an ionic additive that can form a stable, robust interfacial structure on the nickel-rich cathode in ether-based electrolytes. The fluorinated ether 1,1,2,2-tetrafluoroethyl-1H,1H,5H-octafluoropentyl ether (TFOFE) introduced as a cosolvent into ether-based electrolytes stabilizes the electrolytes against oxidation at the LiNi0.8Mn0.1Co0.1O2 (NCM811) cathode while simultaneously preserving the electrochemical performance of the Li metal anode. Lithium difluoro(bisoxalato)phosphate (LiDFBP) forms a uniform cathode-electrolyte interphase that limits the generation of microcracks inside secondary particles and undesired dissolution of transition metal ions such as nickel, cobalt, and manganese from the cathode into the electrolyte. Using TFOFE and LiDFBP in ether-based electrolytes provides an excellent capacity retention of 94.5% in a Li vertical bar NCM811 cell after 100 cycles and enables the delivery of significantly increased capacity at high charge and discharge rates by manipulating the interfaces of both electrodes. This research provides insights into advancing electrolyte technologies to resolve the interfacial instability of nickel-rich cathodes in LMBs

Stable electrode???electrolyte interfaces constructed by fluorine- and nitrogen-donating ionic additives for high-performance lithium metal batteries

The advancement of electrolyte systems has enabled the development of high-performance Li metal batteries (LMBs), which have tackled intractable dendritic Li growth and irreversible Li plating/stripping. In particular, the robust electrode???electrolyte interfaces created by electrolyte additives inhibit the deterioration of the cathode and the Li metal anode during repeated cycles. This paper reports the application of electrode???electrolyte interface modifiers, namely lithium nitrate (LiNO3) and lithium difluoro(bisoxalato) phosphate (LiDFBP) as a N donor and F donor, respectively. LiDFBP and LiNO3 with different electron-accepting abilities construct a mechanically robust, LiF-rich inner solid electrolyte interphase (SEI) and ion-permeable, Li3N-containing outer SEI layers on the Li metal anode, respectively. A well-structured dual-layer SEI capable of transporting Li+ ions is formed on the Li metal anode, while the cathode???electrolyte interface (CEI) on the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode is strengthened. Ether-based electrolytes containing LiDFBP and LiNO3 lead to a long cycle life (600 cycles) of Li|NCM811 full cells at C/2 with 80.9% capacity retention and a high Coulombic efficiency (CE) of 99.94%. Structural optimization of the SEI and CEI provides an opportunity for advancing the practical uses of LMBs

Wide-temperature-range operation of lithium-metal batteries using partially and weakly solvating liquid electrolytes

The optimal design of liquid electrolytes is vital for the build-up of long-lifespan lithium-metal batteries (LMBs) that function over a wide-temperature-range. Tuning the electrolyte solvation-structure using partially-fluorinated ether solvents and constructing stable electrode-electrolyte interfaces using electrolyte additives enhance the electrochemical reversibility of lithium-metal anodes and facilitate the realization of high-capacity cathodes for LMBs. This study reports a partially and weakly solvating electrolyte (PWSE) which enables the stable cycling of LMBs at high-voltages within a wide-temperature range through modulation of an electrolyte local-environment using a low-salt concentration of 1.3 M. 1,2-Bis(1,1,2,2-tetrafluoroethoxy)ethane contains two oxygen atoms that coordinate weakly with Li+-ions; it transforms the 1,2-dimethoxyethane-dominated electrolyte solvation-structure to a more anion-incorporated structure. Moreover, a combination of lithium fluoromalonato(difluoro)borate and silver nitrate strengthens the electrode-electrolyte interfaces and improves the oxidation durability of ether-based electrolytes. The PWSE enables the construction of 4.4 V Li|LiCoO2 full cells with a long-lifespan and high-areal-capacity of 3.12 mA h cm-2. With the aid of electrolyte additives, a partially and weakly solvating electrolyte which is acquired by controlling the local environment of the electrolyte qualifies the stable cycling of LMBs at high voltages over a wide temperature range