Rupesh Rohan Srivastava | National Sun Yat-sen University (original) (raw)

Papers by Rupesh Rohan Srivastava

Lecture Notes in Computer Science, 2010

During engineering design, it is often difficult to quantify product reliability because of insuf... more During engineering design, it is often difficult to quantify product reliability because of insufficient data or information for modeling the uncertainties. In such cases, one needs a reliability estimate when the functional form of the uncertainty in the design variables or parameters cannot be found. In this work, a probabilistic method to estimate the reliability in such cases is implemented

Proceedings of the 13th annual conference on Genetic and evolutionary computation - GECCO '11, 2011

For problems involving uncertainties in design variables and parameters, a bi-objective evolution... more For problems involving uncertainties in design variables and parameters, a bi-objective evolutionary algorithm (EA) based approach to design optimization using evidence theory is proposed and implemented in this paper. In addition to a functional objective, a plausibility measure of failure of constraint satisfaction is minimized. Despite some interests in classical optimization literature, such a consideration in EA is rare. Due

Lithium poly(4-styrene sulfonyl (phenylsulfonyl)imide) (PSSPSI) was synthesized through the Hinsb... more Lithium poly(4-styrene sulfonyl (phenylsulfonyl)imide) (PSSPSI) was synthesized through the Hinsberg reaction. Since the bis(sulfonyl)imide anion is immobilized in the polymer chain, the lithium cation transference number was measured to be 0.87. The weight average number molecular weight (M w) was found to be 105,343 determined by gel permeation chromatography (GPC). A gel polymer electrolyte membrane, comprising of PVDF and PSSPSI, was successfully prepared with the ionic conductivity of 1.1 × 10 −3 S cm −1 at room temperature. The membrane exhibits a wide electrochemical window up to 4.5 V (vs. Li + /Li) and is thermally and mechanically stable. The material is well suited for applications in lithium-ion batteries.

Cationic transference number and ionic conductivity of an electrolyte are among the key parameter... more Cationic transference number and ionic conductivity of an electrolyte are among the key parameters that regulate battery performance. In the present work, we introduce a novel concept of using porous organic frameworks as a single ion-conducting electrolyte for lithium ion batteries. The synthesized lithium functionalized melamine–terephthalaldehyde framework (MTF–Li), a three dimensional porous organo– lithium complex, in a medium of organic solvent exhibits ionic conductivity comparable to the values of typical gel polymer electrolytes, and the battery cell assembled with the membrane of the material performs at both room temperature and at 80 C. The rigid three-dimensional framework, functioning as the anionic part of the electrolyte, reduces the anionic transference number to a minimum. As a consequence, the cationic transference number increases to 0.88, close to unity. In addition, by virtue of its synthesis procedure, the electrolyte displays excellent sustainability at high temperatures, which is important for battery safety as well as for enhancing the performance and longevity of the battery.

We report a polysiloxane based single-ion conducting polymer electrolyte (SIPE) synthesized via a... more We report a polysiloxane based single-ion conducting polymer electrolyte (SIPE) synthesized via a hydrosilylation technique. Styrenesulfonyl(phenylsulfonyl)imide groups were grafted on highly flexible polysiloxane chains followed by lithiation. The highly delocalized anionic charges in the grafted moiety give rise to weak association with lithium ions in the polymer matrix, resulting in a lithium ion transference number close to unity (0.89) and remarkably high ionic conductivity (7.2 Â 10 À4 S cm À1) at room temperature. The high flexibility arising from polysiloxane enables the glass transition temperature (T g) to be below room temperature. The electrolyte membrane displays high thermal stability and a strong mechanical strength. A coin cell assembled with the membrane comprised of the electrolyte and poly(vinylidene-fluoride-co-hexafluoropropene) (PVDF-HFP) performs remarkably well over a wide range of temperatures with high charge–discharge rates.

The development of electrolytes capable of performing at a high voltage (>5 V) is essential for t... more The development of electrolytes capable of performing at a high voltage (>5 V) is essential for the advancement of lithium-ion batteries. In the present work, we have investigated a dinitrile−mononitrile-based electrolyte system that can offer electrochemical stability up to 5.5 V at room temperature. The electrolytes consist of 1.0 M lithium bis(trifluoromethane)sulfonamide in various volume proportions of glutaronitrile, a dinitrile, and butyronitrile, a mononitrile (10/0; 8/2; 6/4; 4/6; 2/8; 10/0). The ionic conductivity of the electrolytes was found to be 3.1 × 10 −3 − 10.6 × 10 −3 S cm −1 at 30 °C, comparable with commercially used carbonate-based electrolytes. However, butyronitrile reacts with Li metal to give 3-amino-2-ethylhex-2-ene-nitrile, 2,6-dipropyl-5-ethylpyrimidin-4-amine, and oligomers/polymers. These compounds have been characterized by nuclear magnetic resonance techniques, and based on these findings, a plausible mechanism of reactivity of mononitriles toward Li metal has been proposed. Finally, 5 wt % of vinylene carbonate is added to the glutaronitrile/butyronitrile (6/4 ratio) system to inhibit the reductive decomposition of butyronitrile. The resultant electrolyte system is used in the assembly of several coin cells consisting of a LiFePO 4 composite cathode and a Li metal anode. The cells perform up to 3 C charge/discharge rate with reasonably good discharge capacity and also display a cycle life of more than 100 cycles at a 0.5 C rate with capacity retention above 95% at room temperature. ■ INTRODUCTION The increasing adverse effects of greenhouse gases, which has been causing the climate change, and rapid exhaustion of fossil fuels have compelled a switch to renewable and clean energy resources. While a plethora of energy is available, courtesy of the sun, wind, and water, the issue of storage and delivery of energy has become an area requiring serious technological advancement. 1−7 Lithium-ion battery technology, which has been powering portable gadgets and light transportation vehicles successfully for decades, could serve the purpose but necessitates significant improvements in energy and power density of the batteries. 8−14 In this context, various high-voltage cathode-active materials, such as LiNiVO 4 , LiNi 0.5 Mn 1.5 O 4 , LiCr x Mn 2−x O 4 , and LiNiPO 4 , have been developed recently, which exhibit working voltages above 5.0 V vs Li/Li +. 15−22 To utilize these cathode materials practically, a coherent electrolyte system is required, which can perform successfully above the 5.0 V benchmark. Unfortunately, the electrochemical stability of conventional carbonate electrolyte solvents is lower than 4.8 V vs Li/Li +. 23−25 Although several high-voltage electrolyte solvents have been reported, such as sulfones, ionic liquids, fluorinated carbonates, and dinitriles, all of these have other issues that limit their utility as a part of high-voltage electrolyte systems. 24,26−37 By virtue of the inherent cathodic stability of cyano groups, the nitrile solvents, mononitriles and dinitriles, could serve as high-voltage electrolyte solvents. It has been well demonstrated that the electrolyte of lithium bis(trifluoromethane)-sulfonamide (LiTFSI) in dinitrile systems possesses a wide working temperature range, excellent high electrochemical stability (∼7.0 V for a single nitrile; 6.0−6.5 V for binary and ternary solvents), and great dielectric permittivity. 27,38,39 In addition, the dinitrile−LiTFSI electrolyte systems can form a protective layer on the Al current collector; this layer reduces corrosion owing to the LiTFSI salt at a high voltage. 24,38−40 However, the high viscosity, which hampers the ionic

A novel linear non-fluorinated sulfonimide functionalized polyamide (SPA) polymer electrolyte was... more A novel linear non-fluorinated sulfonimide functionalized polyamide (SPA) polymer electrolyte was successfully synthesized via an aromatic sulfonimide monomer with superior thermal stability and superacidity. The aromatic sulfonimide remains stable below 220°C. To fabricate membranes with strong mechanical strength and dimensional stability, the polymer was blended with various quantities of PVdF. The PVdF/SPA blend membranes exhibit an excellent capacity of water uptake and high dimensional stability. However, their proton conductivity was found to be substantially lower than that of Nafion 211. Analysis on the SEM images of the PVdF/SPA blend membranes reveals that the low proton conductivity is primarily caused by the large pore structures ([1 lm), which lead to breakdown of the continuous proton transport channels.

A class of sp 3 boron-based polymeric compounds with highly exposed lithium cations is both therm... more A class of sp 3 boron-based polymeric compounds with highly exposed lithium cations is both thermally and electrochemically stable for use in Li-ion batteries. Syntheses of a variety of the sp 3 boron-based polymeric materials can be realized by taking advantage of the well-developed methods used for preparation of metal organic framework compounds.

Lithium poly(4-styrene sulfonyl (phenylsulfonyl)imide) (PSSPSI) was synthesized through the Hinsb... more Lithium poly(4-styrene sulfonyl (phenylsulfonyl)imide) (PSSPSI) was synthesized through the Hinsberg reaction. Since the bis(sulfonyl)imide anion is immobilized in the polymer chain, the lithium cation transference number was measured to be 0.87. The weight average number molecular weight (M w ) was found to be 105,343 determined by gel permeation chromatography (GPC). A gel polymer electrolyte membrane, comprising of PVDF and PSSPSI, was successfully prepared with the ionic conductivity of 1.1 × 10 −3 S cm −1 at room temperature. The membrane exhibits a wide electrochemical window up to 4.5 V (vs. Li + /Li) and is thermally and mechanically stable. The material is well suited for applications in lithium-ion batteries.

A cross-linked organo-magnesium complex (MTF-Mg) was synthesized and investigated for selective C... more A cross-linked organo-magnesium complex (MTF-Mg) was synthesized and investigated for selective CO 2 adsorption over N 2 at 298 K. Remarkably high selectivity and reversibility were achieved with an isosteric heat of adsorption of 45.2 kJ mol À1 for CO 2 , consistent with the predicted DFT value of 37.3 kJ mol À1 .

ambient temperature range have been observed in a number of materials of this class. To date, sig... more ambient temperature range have been observed in a number of materials of this class. To date, signifi cant hydrogen uptake at room temperature has only been observed in compounds of the latter two classes but none of the physisorption materials has been found to exhibit a hydrogen capacity that meets the gravimetric and volumetric targets set by the U.S. Department of Energy. We note here that the surface area of class two materials is in general substantially smaller than that of class-one and class-three compounds with metal hydrazide gel materials as a typical example. The highest hydrogen capacity of the class-three materials reported to date is 1.01 wt% at room temperature and 90 atm, in spite of the large surface area up to 5109 m 2 g −1 , likely attributed to the limited access of the active metal sites available to H 2 molecules. Clearly, an appropriate porosity and abundant adsorption sites are two essential attributes required to induce strong physisorption at a near ambient temperature.

Phenol-and phloroglucinol-based organo-magnesium ionic solid compounds were synthesized for room ... more Phenol-and phloroglucinol-based organo-magnesium ionic solid compounds were synthesized for room temperature hydrogen storage via physisorption. These materials contain magnesium dications balanced with highly charge-delocalized anionic species, making the cations highly exposed with relatively weak electrostatic interactions with the anions, and thus facilitates an interaction with molecular hydrogen. It was found that the driving force for the hydrogen physisorption in these materials is largely electrostatic with the s electrons of hydrogen partially polarized by the cationic charges. The synthesized amorphous complexes exhibit moderate surface areas up to 165 m 2 g À1 and 115 m 2 g À1 with maximum excess hydrogen sorption capacities of 0.22 wt% and 0.8 wt%, respectively, at 298 K and 100 atm. The isosteric heat of adsorption was calculated from Clausius-Clapeyron equation using isotherms at 323 K, 298 K and 273 K. The results confirm low coverage isosteric heat of adsorption of 7.2 kJ mol À1 and 12 kJ mol À1 , respectively.

We report excellent operability of a lithium-ion battery with a gel membrane of an sp 3 boron-bas... more We report excellent operability of a lithium-ion battery with a gel membrane of an sp 3 boron-based single ion polymer, lithium poly(1,2,3,4-butanetetracarboxylic acid borate) (LiPBAB), as the electrolyte. The battery exhibits outstanding performance in a wide temperature range of 25-100 C with high ionic conductivity of 2.9 Â 10 À4 S cm À1 , high electrochemical stability of 4.3 V, a large cationic transference number t + of 0.89 and an excellent mechanical strength of 33 MPa at room temperature. The remarkable cyclic stability of the battery at 100 C demonstrates exceptional device safety enabled by the electrolyte membrane.

Lithium ion batteries single-ion conductor sp 3 boron ionic conductivity a b s t r a c t

Recent research activities on single ion polymer electrolyte (SIPE) that provides a simple but im... more Recent research activities on single ion polymer electrolyte (SIPE) that provides a simple but important way to solve problems related to battery safety and lithium dendrite formation for lithium based battery applications were reviewed. Improvement in both ionic conduction property and battery performance has been achieved during the last two decades. The ionic conduction mechanisms to guide SIPE molecular structure design, membrane preparation and battery assembling have been more clarified. Prototypes with both gel and all-solid systems have been demonstrated with acceptable performance and stability. In addition, the future prospects for the development of SIPE materials in lithium battery applications were also described.

Lithium poly(pyromellitic acid borate) (PPAB) was synthesized via polymerization of lithium tetra... more Lithium poly(pyromellitic acid borate) (PPAB) was synthesized via polymerization of lithium tetramethanolatoborate and silylated pyromellitic acid. The synthesized material was characterized by Fourier transformation infrared spectroscopy, 11 B nuclear magnetic resonance, scanning electron microscopy, and thermogravimetric analysis. And electrochemical characterizations were carried out on the blended PPAB/PVDF-HFP membrane. The PPAB-based composite membrane exhibits high lithium ionic conductivity, a broad electrochemical window and a high lithium-ion transference number. The battery cells assembled with the PPAB/PVDF-HFP/EC:PC composite membrane as the electrolyte perform reasonably well not only at elevated temperature but also at room temperature with good cyclability and discharge capacity, making the material suitable for applications in lithium-ion batteries.

Lecture Notes in Computer Science, 2010

During engineering design, it is often difficult to quantify product reliability because of insuf... more During engineering design, it is often difficult to quantify product reliability because of insufficient data or information for modeling the uncertainties. In such cases, one needs a reliability estimate when the functional form of the uncertainty in the design variables or parameters cannot be found. In this work, a probabilistic method to estimate the reliability in such cases is implemented

Proceedings of the 13th annual conference on Genetic and evolutionary computation - GECCO '11, 2011

For problems involving uncertainties in design variables and parameters, a bi-objective evolution... more For problems involving uncertainties in design variables and parameters, a bi-objective evolutionary algorithm (EA) based approach to design optimization using evidence theory is proposed and implemented in this paper. In addition to a functional objective, a plausibility measure of failure of constraint satisfaction is minimized. Despite some interests in classical optimization literature, such a consideration in EA is rare. Due

Lithium poly(4-styrene sulfonyl (phenylsulfonyl)imide) (PSSPSI) was synthesized through the Hinsb... more Lithium poly(4-styrene sulfonyl (phenylsulfonyl)imide) (PSSPSI) was synthesized through the Hinsberg reaction. Since the bis(sulfonyl)imide anion is immobilized in the polymer chain, the lithium cation transference number was measured to be 0.87. The weight average number molecular weight (M w) was found to be 105,343 determined by gel permeation chromatography (GPC). A gel polymer electrolyte membrane, comprising of PVDF and PSSPSI, was successfully prepared with the ionic conductivity of 1.1 × 10 −3 S cm −1 at room temperature. The membrane exhibits a wide electrochemical window up to 4.5 V (vs. Li + /Li) and is thermally and mechanically stable. The material is well suited for applications in lithium-ion batteries.

Cationic transference number and ionic conductivity of an electrolyte are among the key parameter... more Cationic transference number and ionic conductivity of an electrolyte are among the key parameters that regulate battery performance. In the present work, we introduce a novel concept of using porous organic frameworks as a single ion-conducting electrolyte for lithium ion batteries. The synthesized lithium functionalized melamine–terephthalaldehyde framework (MTF–Li), a three dimensional porous organo– lithium complex, in a medium of organic solvent exhibits ionic conductivity comparable to the values of typical gel polymer electrolytes, and the battery cell assembled with the membrane of the material performs at both room temperature and at 80 C. The rigid three-dimensional framework, functioning as the anionic part of the electrolyte, reduces the anionic transference number to a minimum. As a consequence, the cationic transference number increases to 0.88, close to unity. In addition, by virtue of its synthesis procedure, the electrolyte displays excellent sustainability at high temperatures, which is important for battery safety as well as for enhancing the performance and longevity of the battery.

We report a polysiloxane based single-ion conducting polymer electrolyte (SIPE) synthesized via a... more We report a polysiloxane based single-ion conducting polymer electrolyte (SIPE) synthesized via a hydrosilylation technique. Styrenesulfonyl(phenylsulfonyl)imide groups were grafted on highly flexible polysiloxane chains followed by lithiation. The highly delocalized anionic charges in the grafted moiety give rise to weak association with lithium ions in the polymer matrix, resulting in a lithium ion transference number close to unity (0.89) and remarkably high ionic conductivity (7.2 Â 10 À4 S cm À1) at room temperature. The high flexibility arising from polysiloxane enables the glass transition temperature (T g) to be below room temperature. The electrolyte membrane displays high thermal stability and a strong mechanical strength. A coin cell assembled with the membrane comprised of the electrolyte and poly(vinylidene-fluoride-co-hexafluoropropene) (PVDF-HFP) performs remarkably well over a wide range of temperatures with high charge–discharge rates.

The development of electrolytes capable of performing at a high voltage (>5 V) is essential for t... more The development of electrolytes capable of performing at a high voltage (>5 V) is essential for the advancement of lithium-ion batteries. In the present work, we have investigated a dinitrile−mononitrile-based electrolyte system that can offer electrochemical stability up to 5.5 V at room temperature. The electrolytes consist of 1.0 M lithium bis(trifluoromethane)sulfonamide in various volume proportions of glutaronitrile, a dinitrile, and butyronitrile, a mononitrile (10/0; 8/2; 6/4; 4/6; 2/8; 10/0). The ionic conductivity of the electrolytes was found to be 3.1 × 10 −3 − 10.6 × 10 −3 S cm −1 at 30 °C, comparable with commercially used carbonate-based electrolytes. However, butyronitrile reacts with Li metal to give 3-amino-2-ethylhex-2-ene-nitrile, 2,6-dipropyl-5-ethylpyrimidin-4-amine, and oligomers/polymers. These compounds have been characterized by nuclear magnetic resonance techniques, and based on these findings, a plausible mechanism of reactivity of mononitriles toward Li metal has been proposed. Finally, 5 wt % of vinylene carbonate is added to the glutaronitrile/butyronitrile (6/4 ratio) system to inhibit the reductive decomposition of butyronitrile. The resultant electrolyte system is used in the assembly of several coin cells consisting of a LiFePO 4 composite cathode and a Li metal anode. The cells perform up to 3 C charge/discharge rate with reasonably good discharge capacity and also display a cycle life of more than 100 cycles at a 0.5 C rate with capacity retention above 95% at room temperature. ■ INTRODUCTION The increasing adverse effects of greenhouse gases, which has been causing the climate change, and rapid exhaustion of fossil fuels have compelled a switch to renewable and clean energy resources. While a plethora of energy is available, courtesy of the sun, wind, and water, the issue of storage and delivery of energy has become an area requiring serious technological advancement. 1−7 Lithium-ion battery technology, which has been powering portable gadgets and light transportation vehicles successfully for decades, could serve the purpose but necessitates significant improvements in energy and power density of the batteries. 8−14 In this context, various high-voltage cathode-active materials, such as LiNiVO 4 , LiNi 0.5 Mn 1.5 O 4 , LiCr x Mn 2−x O 4 , and LiNiPO 4 , have been developed recently, which exhibit working voltages above 5.0 V vs Li/Li +. 15−22 To utilize these cathode materials practically, a coherent electrolyte system is required, which can perform successfully above the 5.0 V benchmark. Unfortunately, the electrochemical stability of conventional carbonate electrolyte solvents is lower than 4.8 V vs Li/Li +. 23−25 Although several high-voltage electrolyte solvents have been reported, such as sulfones, ionic liquids, fluorinated carbonates, and dinitriles, all of these have other issues that limit their utility as a part of high-voltage electrolyte systems. 24,26−37 By virtue of the inherent cathodic stability of cyano groups, the nitrile solvents, mononitriles and dinitriles, could serve as high-voltage electrolyte solvents. It has been well demonstrated that the electrolyte of lithium bis(trifluoromethane)-sulfonamide (LiTFSI) in dinitrile systems possesses a wide working temperature range, excellent high electrochemical stability (∼7.0 V for a single nitrile; 6.0−6.5 V for binary and ternary solvents), and great dielectric permittivity. 27,38,39 In addition, the dinitrile−LiTFSI electrolyte systems can form a protective layer on the Al current collector; this layer reduces corrosion owing to the LiTFSI salt at a high voltage. 24,38−40 However, the high viscosity, which hampers the ionic

A novel linear non-fluorinated sulfonimide functionalized polyamide (SPA) polymer electrolyte was... more A novel linear non-fluorinated sulfonimide functionalized polyamide (SPA) polymer electrolyte was successfully synthesized via an aromatic sulfonimide monomer with superior thermal stability and superacidity. The aromatic sulfonimide remains stable below 220°C. To fabricate membranes with strong mechanical strength and dimensional stability, the polymer was blended with various quantities of PVdF. The PVdF/SPA blend membranes exhibit an excellent capacity of water uptake and high dimensional stability. However, their proton conductivity was found to be substantially lower than that of Nafion 211. Analysis on the SEM images of the PVdF/SPA blend membranes reveals that the low proton conductivity is primarily caused by the large pore structures ([1 lm), which lead to breakdown of the continuous proton transport channels.

A class of sp 3 boron-based polymeric compounds with highly exposed lithium cations is both therm... more A class of sp 3 boron-based polymeric compounds with highly exposed lithium cations is both thermally and electrochemically stable for use in Li-ion batteries. Syntheses of a variety of the sp 3 boron-based polymeric materials can be realized by taking advantage of the well-developed methods used for preparation of metal organic framework compounds.

Lithium poly(4-styrene sulfonyl (phenylsulfonyl)imide) (PSSPSI) was synthesized through the Hinsb... more Lithium poly(4-styrene sulfonyl (phenylsulfonyl)imide) (PSSPSI) was synthesized through the Hinsberg reaction. Since the bis(sulfonyl)imide anion is immobilized in the polymer chain, the lithium cation transference number was measured to be 0.87. The weight average number molecular weight (M w ) was found to be 105,343 determined by gel permeation chromatography (GPC). A gel polymer electrolyte membrane, comprising of PVDF and PSSPSI, was successfully prepared with the ionic conductivity of 1.1 × 10 −3 S cm −1 at room temperature. The membrane exhibits a wide electrochemical window up to 4.5 V (vs. Li + /Li) and is thermally and mechanically stable. The material is well suited for applications in lithium-ion batteries.

A cross-linked organo-magnesium complex (MTF-Mg) was synthesized and investigated for selective C... more A cross-linked organo-magnesium complex (MTF-Mg) was synthesized and investigated for selective CO 2 adsorption over N 2 at 298 K. Remarkably high selectivity and reversibility were achieved with an isosteric heat of adsorption of 45.2 kJ mol À1 for CO 2 , consistent with the predicted DFT value of 37.3 kJ mol À1 .

ambient temperature range have been observed in a number of materials of this class. To date, sig... more ambient temperature range have been observed in a number of materials of this class. To date, signifi cant hydrogen uptake at room temperature has only been observed in compounds of the latter two classes but none of the physisorption materials has been found to exhibit a hydrogen capacity that meets the gravimetric and volumetric targets set by the U.S. Department of Energy. We note here that the surface area of class two materials is in general substantially smaller than that of class-one and class-three compounds with metal hydrazide gel materials as a typical example. The highest hydrogen capacity of the class-three materials reported to date is 1.01 wt% at room temperature and 90 atm, in spite of the large surface area up to 5109 m 2 g −1 , likely attributed to the limited access of the active metal sites available to H 2 molecules. Clearly, an appropriate porosity and abundant adsorption sites are two essential attributes required to induce strong physisorption at a near ambient temperature.

Phenol-and phloroglucinol-based organo-magnesium ionic solid compounds were synthesized for room ... more Phenol-and phloroglucinol-based organo-magnesium ionic solid compounds were synthesized for room temperature hydrogen storage via physisorption. These materials contain magnesium dications balanced with highly charge-delocalized anionic species, making the cations highly exposed with relatively weak electrostatic interactions with the anions, and thus facilitates an interaction with molecular hydrogen. It was found that the driving force for the hydrogen physisorption in these materials is largely electrostatic with the s electrons of hydrogen partially polarized by the cationic charges. The synthesized amorphous complexes exhibit moderate surface areas up to 165 m 2 g À1 and 115 m 2 g À1 with maximum excess hydrogen sorption capacities of 0.22 wt% and 0.8 wt%, respectively, at 298 K and 100 atm. The isosteric heat of adsorption was calculated from Clausius-Clapeyron equation using isotherms at 323 K, 298 K and 273 K. The results confirm low coverage isosteric heat of adsorption of 7.2 kJ mol À1 and 12 kJ mol À1 , respectively.

We report excellent operability of a lithium-ion battery with a gel membrane of an sp 3 boron-bas... more We report excellent operability of a lithium-ion battery with a gel membrane of an sp 3 boron-based single ion polymer, lithium poly(1,2,3,4-butanetetracarboxylic acid borate) (LiPBAB), as the electrolyte. The battery exhibits outstanding performance in a wide temperature range of 25-100 C with high ionic conductivity of 2.9 Â 10 À4 S cm À1 , high electrochemical stability of 4.3 V, a large cationic transference number t + of 0.89 and an excellent mechanical strength of 33 MPa at room temperature. The remarkable cyclic stability of the battery at 100 C demonstrates exceptional device safety enabled by the electrolyte membrane.

Lithium ion batteries single-ion conductor sp 3 boron ionic conductivity a b s t r a c t

Recent research activities on single ion polymer electrolyte (SIPE) that provides a simple but im... more Recent research activities on single ion polymer electrolyte (SIPE) that provides a simple but important way to solve problems related to battery safety and lithium dendrite formation for lithium based battery applications were reviewed. Improvement in both ionic conduction property and battery performance has been achieved during the last two decades. The ionic conduction mechanisms to guide SIPE molecular structure design, membrane preparation and battery assembling have been more clarified. Prototypes with both gel and all-solid systems have been demonstrated with acceptable performance and stability. In addition, the future prospects for the development of SIPE materials in lithium battery applications were also described.

Lithium poly(pyromellitic acid borate) (PPAB) was synthesized via polymerization of lithium tetra... more Lithium poly(pyromellitic acid borate) (PPAB) was synthesized via polymerization of lithium tetramethanolatoborate and silylated pyromellitic acid. The synthesized material was characterized by Fourier transformation infrared spectroscopy, 11 B nuclear magnetic resonance, scanning electron microscopy, and thermogravimetric analysis. And electrochemical characterizations were carried out on the blended PPAB/PVDF-HFP membrane. The PPAB-based composite membrane exhibits high lithium ionic conductivity, a broad electrochemical window and a high lithium-ion transference number. The battery cells assembled with the PPAB/PVDF-HFP/EC:PC composite membrane as the electrolyte perform reasonably well not only at elevated temperature but also at room temperature with good cyclability and discharge capacity, making the material suitable for applications in lithium-ion batteries.