POM-based Metal Organic Frameworks with Woven Fabric Structure for Lithium Storage

The development of new anode materials for LIBs with high specific energy density and long cycle performance have been became urgent increasing demand for further applications. Polyoxometalates (POMs), as a...

Designing porous and stable Au coating Ni nanosheets based Ni foam for quasi-symmetric polymer Li–air Batteries

Li–air cells have aroused intense interest because of ultra-high specific energy, but their practical application is still hindered by many problems, such as slurry reaction kinetics and serious parasitic reaction...

High Specific Energy Li7La3Zr2O12 Solid Electrolyte Based Thermal Battery

Garnet-type Ta-doped Li7La3Zr2O12 (LLZTO) solid electrolyte has been widely investigated for secondary Li ionic or metal batteries at ambient temperature. Because of the increasing ionic conductivity of LLZTO with temperature, we applied the LLZTO solid electrolyte to thermal battery working at 550℃. The LLZTO presents ultrahigh specific energy as the discharge specific energy and specific power is 605 W h/kg and 2.74 kW/kg at 100 mA/cm2 with a cut-off voltage of 1.8 V, respectively. This is larger than the LiF–LiCl-LiBr electrolyte which is commonly used in thermal battery with a specific energy of 514 W h/kg. The internal resistance of the single cell reaches 0.65 Ω, but the specific energy remains at about 400 W h/kg as the current density increases to 400 mA/cm2. We report the application of LLZTO in thermal battery with high specific energy, large current, and high voltage discharge for the first time, broadening the application range of solid electrolytes.

Reactive Spray Drying as a One-Step Synthesis Approach towards Si/rGO Anode Materials for Lithium-Ion Batteries

Lithium-ion batteries with Si anodes are still attracting increasing attention, particularly due to the high specific energy density. The main disadvantage of silicon as anode material is its reduced cell performance in terms of cycling stability. One promising approach to improve this is embedding silicon nanoparticles in a graphene-like matrix via spray drying. All processes described so far need a time- and energy-intensive two-step-synthesis to obtain the graphene-like rGO structure. Here, we present a reactive spray drying process for synthesis of Si/rGO composites. For proper reactor design, the reaction kinetics are investigated by simultaneous thermal analysis in various atmospheres. We can describe thermal decomposition of GO to rGO as a second-order reaction. STA data also show that additional presence of water in the atmosphere due to the one-step synthesis is negligible at temperatures below 600 °C for both the reaction of GO and the additional oxidation of Si. To evaluate the electrochemical performance, the composites are cycled in a half cell setup. Delithiation capacity after cell formation could be raised from 252 mAh g-1 for GO to 327 mAh g-1 for rGO. In addition, we are able to synthesize Si-containing composites suitable for the anode of LiB using our process.

Recent advances and future perspectives for aqueous zinc-ion capacitors

The ion hybrid capacitor is expected to combine the high specific energy of battery-type materials and the superior specific power of capacitor-type materials, being considered as a promising energy storage technique. Particularly, the aqueous zinc-ion capacitors (ZIC) possessing merits of high safety, cost-efficiency and eco-friendliness, have been widely explored with various electrode materials and electrolytes to obtain excellent electrochemical performance. In this review, we first summarized the research progress on enhancing the specific capacitance of capacitor-type materials and reviewed the research on improving the cycling capability of battery-type materials under high current densities. Then, we looked back on the effects of electrolyte engineering on the electrochemical performance of ZIC. Finally, the research challenges and development directions of ZIC have been proposed. This review provides a guidance for the design and construction of the high-performance ZIC.

A Perspective on Li/S Battery Design: Modeling and Development Approaches

Lithium/sulfur (Li/S) cells that offer an ultrahigh theoretical specific energy of 2600 Wh/kg are considered one of the most promising next-generation rechargeable battery systems for the electrification of transportation. However, the commercialization of Li/S cells remains challenging, despite the recent advancements in materials development for sulfur electrodes and electrolytes, due to several critical issues such as the insufficient obtainable specific energy and relatively poor cyclability. This review aims to introduce electrode manufacturing and modeling methodologies and the current issues to be overcome. The obtainable specific energy values of Li/S pouch cells are calculated with respect to various parameters (e.g., sulfur mass loading, sulfur content, sulfur utilization, electrolyte-volume-to-sulfur-weight ratio, and electrode porosity) to demonstrate the design requirements for achieving a high specific energy of >300 Wh/kg. Finally, the prospects for rational modeling and manufacturing strategies are discussed, to establish a new design standard for Li/S batteries.

Gel Polymer Electrolyte Based on Methyl Methacrylate for Lithium-Sulfur Batteries

Lithium-sulfur batteries are next-generation battery systems with low cost and high specific energy. However, it is necessary to solve several deficiencies of these batteries such as shuttle effect, and gel polymer electrolyte is a great candidate. These perspective materials can be used as a replacement for liquid electrolytes, and at the same time, they can help to solve the problems of lithium-sulfur batteries. In this work, gel polymer electrolyte (GPE) based on methyl methacrylate was prepared by cross-linking strategy. As cross-link ethylene glycol dimethacrylate (EDMA) was used. Prepared gel with a high electric conductivity was testing in the lithium-sulfur cell (Li/GPE/S). The electrochemical performance of the cell was studied.

Microwave-Induced Polyindole on Cobalt MOF- Electrodes for High-Performance Supercapacitors

Metal-organic frameworks (MOF) are well-known for their high surface area and porous nature. However, their use in energy storage applications remains limited by their poor electrical conductivity. Here, microwave-induced polyindole modified cobalt MOF composite (CoMP) was constructed to address the poor conductivity of cobalt MOF and improve their applicability in energy storage. The electrochemical performance of the CoMP was investigated in 3 M KOH electrolyte. Deliberate mixing of PIn with Cobalt MOF resulted in effective diffusion of PIn nanospheres into the MOF matrix. With the reticulate porous morphology and large surface area, the CoMP electrode could facilitate easy ion transport at the electrode-electrolyte interface and achieve a maximum specific capacitance as high as 432.6 mF cm-2 at 10 mV s-1 surpassing polyindole (284.5 mF cm-2) and cobalt MOF (235.5 mF cm-2). Also, the CoMP symmetric supercapacitor delivered high specific energy (8.2 W h cm-2) and specific power (622 W cm-2) at 2 mA cm-2 with 93% capacitance retention after 5000 GCD cycles.

Development of a Li-Ion Capacitor Pouch Cell Prototype by Means of a Low-Cost, Air-Stable, Solution Processable Fabrication Method

Due to the dual advantage of capacitive and faradaic charge storage mechanisms, Li-ion capacitors (LICs) are regarded as promising energy storage technology for many high-power applications. However, the high cost and intricacy of indispensable pre-lithiation step in LIC fabrication are the major stumbling block against its widespread commercial interest. In this regard, operando pre-lithiation through incorporating lithium-containing sacrificial salt in the positive electrode holds high potential to solve this issue. Herein, we present an industrially compatible fabrication method based on a solution-processable positive electrode consisting of an activated carbon mixed with a low-cost, air-stable dilithium squarate as sacrificial salt. Through careful optimization of electrode design, laboratory-scale cells are up-scaled to pouch cell prototypes. Fabricated LIC pouch cells deliver high specific energy (i.e. max. 58 Wh kg-1AM) and power (i.e. max. 8190 W kg-1AM) with respect to active electrode mass. Moreover, cycle life and floating tests performed at room temperature show capacitance retention of 83 % after 80000 charge-discharge cycles and 100 % retention after 1000 floating hours at 3.8 V. However, the accelerated aging tests at 70 ºC induce fast device failure. Post-mortem analyses reveal different ageing mechanisms for cycled and floated LIC pouch cells.

The Role of Areal Capacity in Determining Short Circuiting of Sulfide-Based Solid-State Batteries

Solid-state batteries (SSBs) with lithium metal anodes offer higher specific energy than conventional lithium-ion batteries, but they must utilize areal capacities >3 mAh cm-2 and cycle at current densities >3 mA cm-2 to achieve commercial viability. Substantial research effort has focused on increasing rate capabilities of SSBs by mitigating detrimental processes such as lithium filament penetration. Less attention has been paid to understanding how areal capacity impacts plating/stripping behavior, despite the importance of areal capacity for achieving high specific energy. Here, we investigate and quantify the relationships among areal capacity, current density, and plating/stripping stability using both symmetric and full-cell configurations with a sulfide solid-state electrolyte (Li6PS5Cl). We show that unstable deposition and short circuiting readily occur at rates much lower than the measured critical current density when a sufficient areal capacity is passed. A systematic study of continuous plating under different electrochemical conditions reveals average “threshold capacity” values at different current densities, beyond which short circuiting occurs. Cycling cells below this threshold capacity significantly enhances cell lifetime, enabling stable symmetric cell cycling at 2.2 mA cm-2 without short circuiting. Finally, we show that full cells also exhibit threshold capacity behavior, but they tend to short circuit at lower current densities and areal capacities. Our results quantify the effects of transferred capacity and demonstrate the importance of using realistic areal capacities in experiments to develop viable solid-state batteries.