scholarly journals Bio-inspired untethered fully soft robots in liquid actuated by induced energy gradients

2019 ◽  
Vol 6 (5) ◽  
pp. 970-981 ◽  
Author(s):  
Liang Xiong Lyu ◽  
Fen Li ◽  
Kang Wu ◽  
Pan Deng ◽  
Seung Hee Jeong ◽  
...  
Keyword(s):  
Energy Density ◽  
Mechanical Performance ◽  
Soft Materials ◽  
High Energy ◽  
High Energy Density ◽  
Soft Robot ◽  
Soft Robots ◽  
Power Sources ◽  
Practical Applications ◽  
Robot Swarm

Abstract Soft robotics with new designs, fabrication technologies and control strategies inspired by nature have been totally changing our view on robotics. To fully exploit their potential in practical applications, untethered designs are preferred in implementation. However, hindered by the limited thermal/mechanical performance of soft materials, it has been always challenging for researchers to implement untethered solutions, which generally involve rigid forms of high energy-density power sources or high energy-density processes. A number of insects in nature, such as rove beetles, can gain a burst of kinetic energy from the induced surface-energy gradient on water to return to their familiar habitats, which is generally known as Marangoni propulsion. Inspired by such a behavior, we report the agile untethered mobility of a fully soft robot in liquid based on induced energy gradients and also develop corresponding fabrication and maneuvering strategies. The robot can reach a speed of 5.5 body lengths per second, which is 7-fold more than the best reported, 0.69 (body length per second), in the previous work on untethered soft robots in liquid by far. Further controlling the robots, we demonstrate a soft-robot swarm that can approach a target simultaneously to assure a hit with high accuracy. Without employing any high energy-density power sources or processes, our robot exhibits many attractive merits, such as quietness, no mechanical wear, no thermal fatigue, invisibility and ease of robot fabrication, which may potentially impact many fields in the future.

scholarly journals Boosting ion dynamics through superwettable leaf-like film based on porous g-C3N4 nanosheets for ionogel supercapacitors

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Minjie Shi ◽  
Cheng Yang ◽  
Chao Yan ◽  
Jintian Jiang ◽  
Yongchao Liu ◽  
...  
Keyword(s):  
Energy Density ◽  
Rate Capability ◽  
High Viscosity ◽  
High Energy ◽  
High Energy Density ◽  
Film Electrode ◽  
Ion Dynamics ◽  
Power Sources ◽  
Practical Applications ◽  
Ion Size

Abstract Ionic liquid (IL) electrolytes have enormous potential for the development of high energy density supercapacitors (SCs) owing to their wide potential windows, but ILs are plagued by sluggish ionic diffusion due to their high viscosity and large ion size. Exploiting superwettable electrodes possessing high compatibility with IL electrolytes remains challenging. Inspired by the biological characteristics observed in nature, a unique film electrode with a Monstera leaf-like nanostructure is synthesized and used to overcome the aforementioned bottleneck. Similar to the pores in Monstera leaves that allow the permeation of air and water vapor, the film electrode is based on porous g-C3N4 nanosheets (~1 nm thick) as ion-accessible “highway” channels, allowing ultrafast diffusion of IL ions. The film exhibits a high diffusion coefficient (3.68 × 10−10 m2 s−1), low activation energy (0.078 mJ mol−1) and extraordinary wettability in the IL electrolyte, indicating its superior IL ion dynamics. As a proof of concept, flexible ionogel SCs (FISCs) with tailorability and editability are fabricated, which exhibit a high energy density (10.5 mWh cm−3), high-power density, remarkable rate capability, and long-term durability, outperforming previously reported FISCs. Importantly, these FISCs can be effectively charged by harvesting sustainable power sources, particularly the rarely studied wind power, for practical applications.

scholarly journals Recent Progress of Metal–Air Batteries—A Mini Review

2019 ◽  
Vol 9 (14) ◽  
pp. 2787 ◽  
Author(s):  
Chunlian Wang ◽  
Yongchao Yu ◽  
Jiajia Niu ◽  
Yaxuan Liu ◽  
Denzel Bridges ◽  
...  
Keyword(s):  
Energy Density ◽  
Lithium Ion ◽  
High Energy ◽  
Rechargeable Batteries ◽  
High Energy Density ◽  
Power Sources ◽  
Electrical Vehicles ◽  
Increasing Demand ◽  
Manufacturing Technologies ◽  
High Level

With the ever-increasing demand for power sources of high energy density and stability for emergent electrical vehicles and portable electronic devices, rechargeable batteries (such as lithium-ion batteries, fuel batteries, and metal–air batteries) have attracted extensive interests. Among the emerging battery technologies, metal–air batteries (MABs) are under intense research and development focus due to their high theoretical energy density and high level of safety. Although significant progress has been achieved in improving battery performance in the past decade, there are still numerous technical challenges to overcome for commercialization. Herein, this mini-review summarizes major issues vital to MABs, including progress on packaging and crucial manufacturing technologies for cathode, anode, and electrolyte. Future trends and prospects of advanced MABs by additive manufacturing and nanoengineering are also discussed.

scholarly journals Synthesis of high-energy-density Pr2Fe14−x Co x B,x⩽3, magnets for practical applications

1995 ◽  
Vol 18 (8) ◽  
pp. 963-974 ◽  
Author(s):  
S Haldar ◽  
S Ram ◽  
P Ramachandrarao ◽  
H D Banerjee
Keyword(s):  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
Practical Applications

High-Performance Asymmetric Supercapacitors Based on the Ni1.5Co1.5S4@CNTs Nanocomposites

NANO ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. 2050136
Author(s):  
Xuan Zheng ◽  
Xingxing He ◽  
Jinlong Jiang ◽  
Zhengfeng Jia ◽  
Yu Li ◽  
...  
Keyword(s):  
Energy Density ◽  
Power Density ◽  
High Performance ◽  
Specific Capacity ◽  
Negative Electrode ◽  
High Energy ◽  
Cycling Stability ◽  
Power Delivery ◽  
High Energy Density ◽  
Practical Applications

In this paper, the Ni[Formula: see text]Co[Formula: see text]S4@CNTs nanocomposites containing different carbon nanotubes (CNT) content were prepared by a one-step hydrothermal method. More hydroxyl and carboxyl groups were introduced on the surface of CNTs by acidizing treatment to increase the dispersion of CNTs. The acid-treated CNTs can more fully compound with Ni[Formula: see text]Co[Formula: see text]S4 nanoparticles to form heterostructure. When the CNTs content is 10[Formula: see text]wt.%, the Ni[Formula: see text]Co[Formula: see text]S4@CNTs-10 nanocomposite exhibits the highest specific capacity of 210[Formula: see text]mAh[Formula: see text]g[Formula: see text] in KOH aqueous electrolytes at current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text]. The superior performances of the Ni[Formula: see text]Co[Formula: see text]S4@CNTs-10 nanocomposite are attributed to the effective synergic effects of the high specific capacity of Ni[Formula: see text]Co[Formula: see text]S4 and the excellent conductivity of CNTs. An asymmetric supercapacitor (ASC) was assembled based on Ni[Formula: see text]Co[Formula: see text]S4@CNTs-10 positive electrode and activated carbon (AC) negative electrode, which delivers a high energy density of 61.2[Formula: see text]Wh[Formula: see text]kg[Formula: see text] at a power density of 800[Formula: see text]W[Formula: see text]kg[Formula: see text], and maintains 34.8[Formula: see text]Wh[Formula: see text]kg[Formula: see text] at a power density of 16079[Formula: see text]W[Formula: see text]kg[Formula: see text]. Also, the ASC device shows an excellent cycling stability with 91.49% capacity retention and above 94% Columbic efficiency after 10 000 cycles at 10[Formula: see text]A[Formula: see text]g[Formula: see text]. This aqueous asymmetric Ni[Formula: see text]Co[Formula: see text]S4@CNTs//AC supercapacitor is promising for practical applications due to its advantages such as high energy density, power delivery and cycling stability.

scholarly journals The Rise of Flexible Zinc-Ion Hybrid Capacitors: Advances, Challenges, and Outlooks

2021 ◽  
Author(s):  
Cheng Wang ◽  
Xin Zeng ◽  
Patrick Cullen ◽  
Zengxia Pei
Keyword(s):  
Energy Density ◽  
Electronic Devices ◽  
High Energy ◽  
Zinc Ion ◽  
High Energy Density ◽  
Power Sources ◽  
Flexible Electronic ◽  
Hybrid Capacitors ◽  
Flexible Electronic Devices

The advent of flexible electronic devices has raised urgent demand for compatible flexible power sources. Zinc-ion hybrid capacitors (ZIHCs) combine the complementary advantages of zinc-ion batteries for high energy density...

Microfluidic Fuel Cells as Microscale Power Sources and Analytical Platforms

2009 ◽  
Author(s):  
Fikile R. Brushett ◽  
Adam S. Hollinger ◽  
Larry J. Markoski ◽  
Paul J. A. Kenis
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Energy Density ◽  
Laminar Flow ◽  
High Energy ◽  
Electrochemical Analysis ◽  
High Energy Density ◽  
Liquid Fuels ◽  
Power Sources ◽  
Microscale Transport

A continuously growing need for high energy density miniaturized power sources for portable electronic applications has spurred the development of a variety of microscale fuel cells. For portable applications, membrane-based fuel cells using small organic fuels (i.e., methanol, formic acid) are among the most promising configurations as they benefit from the high energy density and easy storage of the liquid fuels. Unfortunately, the performance of these fuel cells is often hindered by membrane-related issues such as water management (i.e., electrode dry-out / flooding) and fuel crossover. Furthermore, high costs of, for example, catalysts and membranes as well as durability concerns still hinder commercialization efforts. To address these challenges we have developed membraneless laminar flow-based fuel cells (LFFCs), which exploit microscale transport phenomena (laminar flow) to compartmentalize streams within a single microchannel. The properties of various fuel and media flexible LFFCs will be presented and novel strategies for improving fuel utilization and power density will be discussed. Furthermore, the performance of a scaled-out 14-channel LFFC prototype is presented. We have also developed a microfluidic fuel cell as a powerful analytical platform to investigate and optimize the complex processes that govern the performance of catalysts and electrodes in an operating fuel cell. This platform bridges the gap between a conventional 3-electrode electrochemical cell and a fuel cell, as it allows for standard electrochemical analysis (e.g., CV, CA, EIS) as well as fuel cell analysis (e.g., IV curves).

scholarly journals 3D Printing of NiCoP/Ti3C2 MXene Architectures for Energy Storage Devices with High Areal and Volumetric Energy Density

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Lianghao Yu ◽  
Weiping Li ◽  
Chaohui Wei ◽  
Qifeng Yang ◽  
Yuanlong Shao ◽  
...  
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
3D Printing ◽  
High Energy ◽  
High Energy Density ◽  
High Mass ◽  
Mass Loading ◽  
Energy Storage Devices ◽  
Practical Applications ◽  
3D Printed

AbstractDesigning high-performance electrodes via 3D printing for advanced energy storage is appealing but remains challenging. In normal cases, light-weight carbonaceous materials harnessing excellent electrical conductivity have served as electrode candidates. However, they struggle with undermined areal and volumetric energy density of supercapacitor devices, thereby greatly impeding the practical applications. Herein, we demonstrate the in situ coupling of NiCoP bimetallic phosphide and Ti3C2 MXene to build up heavy NCPM electrodes affording tunable mass loading throughout 3D printing technology. The resolution of prints reaches 50 μm and the thickness of device electrodes is ca. 4 mm. Thus-printed electrode possessing robust open framework synergizes favorable capacitance of NiCoP and excellent conductivity of MXene, readily achieving a high areal and volumetric capacitance of 20 F cm−2 and 137 F cm−3 even at a high mass loading of ~ 46.3 mg cm−2. Accordingly, an asymmetric supercapacitor full cell assembled with 3D-printed NCPM as a positive electrode and 3D-printed activated carbon as a negative electrode harvests remarkable areal and volumetric energy density of 0.89 mWh cm−2 and 2.2 mWh cm−3, outperforming the most of state-of-the-art carbon-based supercapacitors. The present work is anticipated to offer a viable solution toward the customized construction of multifunctional architectures via 3D printing for high-energy-density energy storage systems.

Towards practical cells: Combined use of sparingly solvating electrolyte and titanium black as cathode additive for high-energy-density lithium–sulfur batteries

2021 ◽  
Author(s):  
Masayoshi Watanabe ◽  
Jiali Liu ◽  
Shanglin Li ◽  
Mayeesha Marium ◽  
Binshen Wang ◽  
...  
Keyword(s):  
Energy Density ◽  
Raw Materials ◽  
Low Cost ◽  
High Energy ◽  
High Energy Density ◽  
Practical Applications ◽  
Combined Use ◽  
Lithium Sulfur Batteries ◽  
Cathode Additive ◽  
Lithium Sulfur

The lithium–sulfur (Li–S) battery is considered one of the most promising technologies for next-generation energy storage. To realise its practical applications, electrodes with high areal sulfur loading, low-cost raw materials,...

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