Heterogeneous intercalated metal-organic framework active materials for fast-charging non-aqueous Li-ion capacitors

Dual-Carbon Phase-Encapsulated Prelithiated SiOx Microrod Anode for Lithium-Ion Batteries

Among silicon-based anode family for Li-ion battery technology, SiOx, a nonstoichiometric silicon suboxide holds the potential for significant near-term commercial impact. In this context, this study mainly focuses on demonstrating an innovative SiOx@C anode design that adopts a pre-lithiation strategy based on in situ pyrolysis of Li-salt of silsesquioxane trisilanolate without the need for lithium metal or active lithium compounds and creates dual carbon encapsulation of SiOC nanodomains by simply one-step thermal treatment. This ingenious design ensures the pre-lithiation process and pre-lithiation material with high-environmental stability. Moreover, phenyl-rich organosiloxane clusters and polyacrylonitrile polymers are expected to serve as internal and external carbon source, respectively. The formation of an interpenetrating and continuous carbon matrix network would not only synergistically offer an improved electrochemical accessibility of active sites but also alleviate the volume expansion effect during cycling. As a result, this new type of anode delivered a high reversible capacity, remarkable cycle stability as well as excellent high-rate capability. In particular, the L2-SiOx@C material has a high initial coulomb efficienc of 80.4% and, after 500 cycles, a capacity retention as high as 97.5% at 0.5 A g-1 with a reversible specific capacity of 654.5 mA h g-1.

Developments in conducting polymer-, metal oxide-, and carbon nanotube-based composite electrode materials for supercapacitors: a review

Supercapacitors are the latest development in the field of energy storage devices (ESDs). A lot of research has been done in the last few decades to increase the performance of supercapacitors. The electrodes of supercapacitors are modified by composite materials based on conducting polymers, metal oxide nanoparticles, metal-organic frameworks, covalent organic frameworks, MXenes, chalcogenides, carbon nanotubes (CNTs), etc. In comparison to rechargeable batteries, supercapacitors have advantages such as quick charging and high power density. This review is focused on the progress in the development of electrode materials for supercapacitors using composite materials based on conducting polymers, graphene, metal oxide nanoparticles/nanofibres, and CNTs. Moreover, we investigated different types of ESDs as well as their electrochemical energy storage mechanisms and kinetic aspects. We have also discussed the classification of different types of SCs; advantages and drawbacks of SCs and other ESDs; and the use of nanofibres, carbon, CNTs, graphene, metal oxide-nanofibres, and conducting polymers as electrode materials for SCs. Furthermore, modifications in the development of different types of SCs such as pseudo-capacitors, hybrid capacitors, and electrical double-layer capacitors are discussed in detail; both electrolyte-based and electrolyte-free supercapacitors are taken into consideration. This review will help in designing and fabricating high-performance supercapacitors with high energy density and power output, which will act as an alternative to Li-ion batteries in the future.

Zinc-copper dual-ion electrolytes to suppress dendritic growth and increase anode utilization in zinc ion capacitors

The main bottlenecks that hinder the performance of rechargeable zinc electrochemical cells are their limited cycle lifetime and energy density. To overcome these limitations, this work studied the mechanism of a dual-ion Zn-Cu electrolyte to suppress dendritic formation and extend the device cycle life while concurrently enhancing the utilization ratio of zinc and thereby increasing the energy density of zinc ion capacitors (ZICs). The ZICs achieved a best-in-class energy density of 41 watt hour per kilogram with a negative-to-positive (n/p) electrode capacity ratio of 3.10. At the n/p ratio of 5.93, the device showed a remarkable cycle life of 22,000 full charge-discharge cycles, which was equivalent to 557 hours of discharge. The cumulative capacity reached ~581 ampere hour per gram, surpassing the benchmarks of lithium and sodium ion capacitors and highlighting the promise of the dual-ion electrolyte for delivering high-performance, low-maintenance electrochemical energy supplies.

Crystal structure of dilithium biphenyl-4,4'-di-sulfonate dihydrate

The asymmetric unit of the title compound, μ-biphenyl-4,4'-di-sulfonato-bis-(aqua-lithium), [Li2(C12H8O6S2)(H2O)2] or Li2[Bph(SO3)2](H2O)2, consists of an Li ion, half of the diphenyl-4,4'-di-sulfonate [Bph(SO3 -)2] ligand, and a water mol-ecule. The Li ion exhibits a four-coordinate tetra-hedral geometry with three oxygen atoms of the Bph(SO3 -)2 ligands and a water mol-ecule. The tetra-hedral LiO4 units, which are inter-connected by biphenyl moieties, form a layer structure parallel to (100). These layers are further connected by hydrogen-bonding inter-actions to yield a three-dimensional network.