• Energy Research

Lithium-ion batteries (LIBs) have matured as a technology and serve as power sources in a wide range of applications. Nonetheless, emerging applications, represented by electric vehicles, have been imposing ever-challenging criteria with regard to the key electrochemical properties. Low-resistance anodes are highly desired for high-power and supercharging capabilities of LIBs, and these properties are collectively determined by the electrolyte composition and electrode binder. Here, we report the use of glycerol as an additive to the conventional styrene-butadiene rubber/carboxymethyl cellulose (SBR/CMC) binder for graphite anodes with the aim of lowering the interfacial resistance and thus improving the operating capability at high C-rates. Glycerol, as a plasticizer, increases the interchain free volume in the binder network and also promotes the dissociation of lithium salt owing to its high dielectric constant, both of which jointly facilitate lithium ion diffusion at the anode interface. As a result, the addition of a small amount (0.18 wt% of the entire electrode) of glycerol enhances the high-rate capability (i.e., >1 C). This study highlights the usefulness of small molecules as binder additives for improving the key performance parameters of LIBs without sacrificing other critical properties.

A framework is proposed for accurately predicting the future aging pathways of lithium-ion batteries operated under dynamic conditions by utilizing their path-dependent degradation characteristics.

Sulfated-zirconia superacid enhances the performance of lithium-metal battery markedly by increasing the lithium-ion transference number and modifying the interfacial composition.

Abstract With the aim of attaining a better understanding of the thermal stabilities of solid electrolyte interphase (SEI) layers with lithium salts, a series of lithium alkyl carbonates, including lithium methyl carbonate (LMC) and lithium ethyl carbonate (LEC), were synthesized as model reference SEI components. The effects of the lithium salts, lithium hexafluorophosphate (LiPF 6 ) and lithium bis(oxalate) borate (LiBOB), on the thermal stabilities of the lithium alkyl carbonates were then investigated via the differential scanning calorimetry (DSC) method. It was demonstrated that small and broad exothermic peaks near 100 °C for pure lithium alkyl carbonates were drastically increased, likely due to vigorous synergic exothermal reactions between the lithium alkyl carbonates and LiPF 6 . In contrast, LiBOB did not show increased peaks.

N-doped sites at CNT and graphene trigger spontaneous encapsulation of Si particles by simple pH control at room temperature. Significantly, N-doped CNT encapsulated Si composite electrode materials show remarkable cycle life and rate performance in battery operations. Superior capacity retention of 79.4% is obtained after 200 cycles and excellent rate capability of 914 mA h g−1 is observed at a 10 C rate.

The millipede's extraordinary adhesion provides a design principle for silicon anode binders with emphasis on the superstructure and electrostatic charge.

Recently there is strong interest in lightweight, flexible, and wearable electronics to meet the technological demands of modern society. Integrated energy storage devices of this type are a key area that is still significantly underdeveloped. Here, we describe wearable power devices using everyday textiles as the platform. With an extremely simple "dipping and drying" process using single-walled carbon nanotube (SWNT) ink, we produced highly conductive textiles with conductivity of 125 S cm(-1) and sheet resistance less than 1 Omega/sq. Such conductive textiles show outstanding flexibility and stretchability and demonstrate strong adhesion between the SWNTs and the textiles of interest. Supercapacitors made from these conductive textiles show high areal capacitance, up to 0.48F/cm(2), and high specific energy. We demonstrate the loading of pseudocapacitor materials into these conductive textiles that leads to a 24-fold increase of the areal capacitance of the device. These highly conductive textiles can provide new design opportunities for wearable electronics and energy storage applications.

Entropymetry is proposed as a non-destructive diagnosis tool in detecting structural evolution of LiCoO2and its nickel-doped derivatives.