Lithium difluoro­(oxalato)borate tetra­methyl­ene sulfone disolvate

The title compound, Li+·C2BF2O4 −·2C4H8O2S, is a dimeric species, which resides across a crystallographic inversion center. The dimers form eight-membered rings containing two Li+ cations, which are joined by O2S sulfone linkages. The Li+ cations are ligated by four O atoms from the anions and solvent mol­ecules, forming a pseudo-tetra­hedral geometry. The exocyclic coordination sites are occupied by O atoms from the oxalate group of the difluoro­(oxalato)borate anion and an additional tetra­methyl­ene sulfone ligand

Multifunctional semi-interpenetrating polymer network-nanoencapsulated cathode materials for high-performance lithium-ion batteries

As a promising power source to boost up advent of next-generation ubiquitous era, high-energy density lithium-ion batteries with reliable electrochemical properties are urgently requested. Development of the advanced lithium ion-batteries, however, is staggering with thorny problems of performance deterioration and safety failures. This formidable challenge is highly concerned with electrochemical/thermal instability at electrode material-liquid electrolyte interface, in addition to structural/chemical deficiency of major cell components. Herein, as a new concept of surface engineering to address the abovementioned interfacial issue, multifunctional conformal nanoencapsulating layer based on semi-interpenetrating polymer network (semi-IPN) is presented. This unusual semi-IPN nanoencapsulating layer is composed of thermally-cured polyimide (PI) and polyvinyl pyrrolidone (PVP) bearing Lewis basic site. Owing to the combined effects of morphological uniqueness and chemical functionality (scavenging hydrofluoric acid that poses as a critical threat to trigger unwanted side reactions), the PI/PVP semi-IPN nanoencapsulated-cathode materials enable significant improvement in electrochemical performance and thermal stability of lithium-ion batteries.open

Liquid electrolyte based on lithium bis-fluorosulfonyl imide salt: aluminum corrosion studies and lithium ion battery investigations

Peer reviewed: YesNRC publication: Ye

Solid electrolyte based on succinonitrile and LiBOB : Interface stability and application in lithium batteries

This paper reports physical and electrochemical properties of a solid electrolyte for lithium batteries formed by doping a plastic crystal solvent, succinonitrile, with lithium bioxalato borate (LiBOB). Thermal properties, solubility limits, conductivity, compatibility with lithium, and range of electrochemical stability have been studied. Succinonitrile doped with 4 mol % LiBOB is a solid at room temperature and melts near 50\ub0C. Electrochemical cells employing either LiFePO\u2084 or Li\u2081.\u2082Mn\u2080.\u2084Ni\u2080.\u2083Co\u2080.\u2081O\u2082 as the active cathode material and lithium metal as the anode were evaluated. This solid electrolyte showed excellent performance when combined with a LiFePO\u2084 cathode, delivering a reversible discharge capacity of ~142 mAh g\u207b\ub9 with very good capacity retention. However, with the Li\u2081.\u2082Mn\u2080.\u2084Ni\u2080.\u2083Co\u2080.\u2081O\u2082 cathode, the cell\u2019s capacity retention was not as good exhibiting a discharge capacity that decreased from 194 mAh g\u207b\ub9 in the first cycle to 149 mAh g\u207b\ub9 at 20th cycle.Peer reviewed: YesNRC publication: Ye

In-situ XRD study of the succinonitrile-lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) phase diagram

The salt lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) when dissolved in plastic crystal succinonitrile has been demonstrated to have particularly good conductivity even at room temperature. In-situ X-ray diffraction (XRD) measurements have previously proved invaluable in interpreting the differential scanning calorimetry (DSC) behavior, but the practical lower temperature limit of approximately 1245 \ub0C was higher than the 12100 \ub0C starting temperature of the DSC measurements, and the important crystalline to plastic crystal transition of succinonitrile. An improved cryo-flow system capable of capillary sample temperatures down to 12192 \ub0C without icing can now easily match the DSC conditions. The previously puzzling DSC behavior of the succinonitrile\u2013LiTFSI phase diagram at low temperatures has now been explained, with a surprising formation of a TFSI-rich adduct on heating from 12100 \ub0C even at concentrations as low as 2 mol%.Peer reviewed: YesNRC publication: Ye