Wide temperature range-and damage-tolerant microsupercapacitors from salt-tolerant, anti-freezing and self-healing organohydrogel via dynamic bonds modulation

The advance of microelectronics requires the micropower of microsupercapacitors(MSCs) to possess wide temperature-and damage-tolerance beyond high areal energy density.The properties of electrolyte are crucial for MSCs to meet the above requirements.Here,an organohydrogel electrolyte,featured with high salt tolerance,ultralow freezing point,and strong self-healing ability,is experimentally realized via modulating its inner dynamic bonds.Spectroscopic and theoretical analysis reveal that dimethyl sulfoxide has the ability to reconstruct Li^(+)solvation structure,and interact with free water and polyvinyl alcohol chains via forming hydrogen bonds.The organohydrogel electrolyte is employed to build MSCs,which show a boosted energy density,promising wide temperature range-and damage-tolerant ability.These attractive features make the designed organohydrogel electrolyte have great potential to advance MSCs.

Highly efficient H-bonding charge-transfer complex for microsupercapacitors under extreme conditions of low temperatures

Owing to sluggish ionic mobility at low temperatures, supercapacitors, as well as other energy-storage devices, always suffer from severe capacity decay and even failure under extreme low-temperature circumstances. Solar-thermal-enabled self-heating promises an attractive approach to overcome this issue.Here, we report a unique H-bonding charge-transfer complex with a high photothermal conversion efficiency of 79.5% at 405 nm based on chloranilic acid and albendazole. Integrated with a microsupercapacitor, the chloranilic acid-albendazole complex(CAC) film prompts an apparent temperature increase of 22.7 °C under 1 sun illumination at-32.6 °C, effectively elevating the working temperature of devices.As a result, the rate capability of the microsupercapacitor has been significantly improved with a 17-fold increase in capacitance at a current density of 60 μA cm^(-2), leading to outstanding low-temperature performances. Importantly, the integrated device is capable of working at a low temperature of-30 °C in the open air, which demonstrates the potential of CAC in practical applications for low-temperature ultracapacitive energy-storage devices.

High-rate metal-free MXene microsupercapacitors on paper substrates

MXene is a promising energy storage material for miniaturized microbatteries and microsupercapacitors(MSCs).Despite its superior electrochemical performance,only a few studies have reported MXene-based ultrahigh-rate(>1000 mV s^(−1))on-paper MSCs,mainly due to the reduced electrical conductance of MXene films deposited on paper.Herein,ultrahigh-rate metal-free on-paper MSCs based on heterogeneous MXene/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)-stack electrodes are fabricated through the combination of direct ink writing and femtosecond laser scribing.With a footprint area of only 20 mm^(2),the on-paper MSCs exhibit excellent high-rate capacitive behavior with an areal capacitance of 5.7 mF cm^(−2)and long cycle life(>95%capacitance retention after 10,000 cycles)at a high scan rate of 1000 mV s^(−1),outperforming most of the present on-paper MSCs.Furthermore,the heterogeneous MXene/PEDOT:PSS electrodes can interconnect individual MSCs into metal-free on-paper MSC arrays,which can also be simultaneously charged/discharged at 1000 mV s^(−1),showing scalable capacitive performance.The heterogeneous MXene/PEDOT:PSS stacks are a promising electrode structure for on-paper MSCs to serve as ultrafast miniaturized energy storage components for emerging paper electronics.

Engineering Geometric Electrodes for Electric Field-Enhanced High-Performance Flexible In-Plane Micro-Supercapacitors

In plane micro-supercapacitors that are miniaturized energy storage components have attracted significant attention due to their high power densities for various ubiquitous and sustainable device systems as well as their facile integration on various flexible/wearable platform.To implement the micro-supercapacitors in various practical applications that can accompany solid state or gel electrolyte and flexible substrates,ions must be readily transported to electrodes for achieving high power densities.Herein,we show large enhancement in electrochemical properties of flexible,inplane micro-supercapacitor using sharp-edged interdigitated electrode design,which was simply fabricated through direct laser scribing method.The sharp-edged electrodes allowed strong electric field to be induced at the corners of the electrode fingers which led to the greater accumulation of ions near the surface of electrode,significantly enhancing the energy storage performance of micro-supercapacitors.The electric field-enhanced in-plane micro-supercapacitor showed the volumetric energy density of 1.52 Wh L^(−1)and the excellent cyclability with capacitive retention of 95.4%after 20000 cycles.We further showed various practicability of our sharp-edged design in micro-supercapacitors by showing circuit applicability,mechanical stability,and air stability.These results present an important pathway for designing electrodes in various energy storage devices.

Pushing the Electrochemical Performance Limits of Polypyrrole Toward Stable Microelectronic Devices

Conducting polymers have achieved remarkable attentions owing to their exclusive characteristics,for instance,electrical conductivity,high ionic conductivity,visual transparency,and mechanical tractability.Surface and nanostructure engineering of conjugated conducting polymers offers an exceptional pathway to facilitate their implementation in a variety of scientific claims,comprising energy storage and production devices,flexible and wearable optoelectronic devices.A two-step tactic to assemble high-performance polypyrrole(PPy)-based microsupercapacitor(MSC)is utilized by transforming the current collectors to suppress structural pulverization and increase the adhesion of PPy,and then electrochemical co-deposition of PPy-CNT nanostructures on rGO@Au current collectors is performed.The resulting fine patterned MSC conveyed a high areal capacitance of 65.9 mF cm^(−2)(at a current density of 0.1 mA cm^(−2)),an exceptional cycling performance of retaining 79%capacitance after 10,000 charge/discharge cycles at 5 mA cm^(−2).Benefiting from the intermediate graphene,current collector free PPy-CNT@rGO flexible MSC is produced by a facile transfer method on a flexible substrate,which delivered an areal capacitance of 70.25 mF cm^(−2) at 0.1 mA cm^(−2) and retained 46%of the initial capacitance at a current density of 1.0 mA cm^(−2).The flexible MSC is utilized as a skin compatible capacitive micro-strain sensor with excellent electromechanochemical characteristics.

Recent developments of stamped planar micro-supercapacitors: Materials,fabrication and perspectives

The rapid development of wearable and portable electronics has dramatically increased the application for miniaturized energy storage components.Stamping micro-supercapacitors(MSCs)with planar interdigital configurations are considered as a promising candidate to meet the requirements.In this review,recent progress of the different stamping materials and various stamping technologies are first discussed.The merits of each material,manufacturing process of each stamping method and the properties of stamping MSCs are scrutinized,respectively.Further insights on technical difficulties and scientific challenges are finally demonstrated,including the limited thickness of printed electrodes,poor overlay accuracy and printing resolution.

Emerging miniaturized energy storage devices for microsystem applications:from design to integration

The rapid progress of micro/nanoelectronic systems and miniaturized portable devices has tremendously increased the urgent demands for miniaturized and integrated power supplies.Miniaturized energy storage devices(MESDs),with their excellent properties and additional intelligent functions,are considered to be the preferable energy supplies for uninterrupted powering of microsystems.In this review,we aim to provide a comprehensive overview of the background,fundamentals,device configurations,manufacturing processes,and typical applications of MESDs,including their recent advances.Particular attention is paid to advanced device configurations,such as two-dimensional(2D)stacked,2D planar interdigital,2D arbitrary-shaped,three-dimensional planar,and wire-shaped structures,and their corresponding manufacturing strategies,such as printing,scribing,and masking techniques.Additionally,recent developments in MESDs,including microbatteries and microsupercapacitors,as well as microhybrid metal ion capacitors,are systematically summarized.A series of on-chip microsystems,created by integrating functional MESDs,are also highlighted.Finally,the remaining challenges and future research scope on MESDs are discussed.

Boosting the electrochemical performance and reliability of conducting polyme microelectrode via intermediate graphene for on-chip asymmetric micro-supercapacitor

High-performance anode is hurdle for on-chip planar microsupercapacitor(MSC).Polypyrrole(PPy)is a highly attractive pseudocapacitive material,but its low cycling stability,and low adhesion with current collector hinder its practicability.Herein we propose one-prong generic strategy to boost the cycling stability of PPy.For our strategy,the electrochemical deposition of multilayered reduced graphene oxide(rGO)on micropatterned Au is utilized,and the resultant rGO@Au pattern is then used for growing highly porous PPy nanostructures by facile electrochemical polymerization.The fabricated PPy anode on rGO@Au has quasi rectangular cyclic voltammetry curves up to-0.7 V and exceptional cycling stability,retaining82%of capacitance after 10,000 charge/discharge cycles in 2 M KCl electrolyte.The outstanding reliability of PPy on rGO@Au is due to the flexibility of rGO,accommodating structural pulverization and providing a promising background for the nucleation of highly porous nanostructure.Further,an all-polymer based asymmetric aqueous MSC(AMSC)is constructed with PPy anode and PEDOT cathode,which exhibited excellent electrochemical performance compared with conventional symmetric MSCs based on conducting polymers.The constructed AMSC delivered a maximum areal capacitance of 15.9 m F cm^-2(99.3 F cm^-3),high specific energy and power densities of 4.3μWh cm^-2(27.03 mWh cm^-3)and 0.36 W cm^-2(0.68 W cm^-3)at 1.4 V,respectively.The enhanced electrochemical performances can be illustrated by nucleation mechanism,in which surface topology of r GO generates a promising background for nucleation and electrochemical growth of nanoporous pseudocapacitive conducting polymers with superior interfacial contact and improved surface area.

All-solid-state flexible microsupercapacitor based on two-dimensional titanium carbide

MXenes,serving as a novel family of two-dimensional(2D) metal carbides,have attracted great research interest as one of the promising electrode materials due to the unique properties.However,to our best knowledge,the 2D titanium carbide(one kind of MXene) used in constructing microsupercapacitors(MSCs) has not yet been reported to date.To this end,we firstly produce the MXene films on various kinds of substrates including polyethylene terephthalate(PET),silicon oxide film and titanium plate through vacuum-filtrating and subsequent controlled transferring.On this basis,flexible all-solid-state symmetric MSCs on PET substrate based on MXene films are fabricated by micro-fabrication process using polyvinyl alcohol(PVA)/H_2SO_4 as gel electrolyte.The results show that the as-made MSC has an ultrahigh rate performance with the scan rate of up to 1000Vs^(-1) as well as an ultrafast frequency response(τ_0 = 0.5 ms).In addition,the MSC delivers a large volumetric capacitance of 1.44 F cm^(-3),a high volumetric energy density(0.2 mWh cm^(-3) at the current density of 0.288 A cm^(-3) and a good cycling stability.Our research results presented here may pave the way for a new potential application of MXene in micro-power suppliers and micro-energy storage devices.

One-step laser induced conversion of a gelatin-coated polyimide film into graphene:Tunable morphology,surface wettability and microsupercapacitor applications

Latest advances have witnessed the laser induction process on polyimide(PI)films for the formation of porous graphene.Herein,a fully converted graphene film was prepared by Nd:YAG laser scribing a gelatin coated PI film.It was found that the gelatin played the role of"shield"well in absorbing intense laser impact and benefit for the surface morphology modulation.Laser treatment lower than a critical fluence point of~4.00 J mm^(-2) contributed to a crater-like surface morphology due to the dispersed nature of Nd:YAG laser beam.By tuning laser fluence above the threshold,carbonized surface turned into continuous morphology.A fluid dynamics process accompanied by outgassing occurred during the carbonization,and the surface morphology gradually varied from stretched droplets to porous strips and finally to amorphous porous structures.The morphology evolution in combination with surface chemistry is responsible for the significant wettability transition from superhydrophobic to superhydrophilic,and a Janus superhydrophobic/superhydrophilic surface wettability was achieved under a laser fluence of~8.00 J mm^(-2).Eventually,microsupercapacitors(MSCs)were fabricated to show the great potential of our prepared graphene in flexible electronics.

All-Ti3C2TA:MXene Based Flexible On-chip Microsupercapacitor Array

Flexible on-chip microsupercapacitors(MSCs)are highly desired for integrated wearable or portable elec-tromics due to their advantages of small size,high power density,easy integration,long lifespan,high security,and tlexibility.The output voltage of MSCs can be improved by designing MSC arrays,which could further expand their application fields.In this work,we proposed a facile laser direct cutting method to prepare an on-chip flexible MSC array using TiC,T,MXene as both current collector and electrode materials.The designed MSC in PVAH2SO4 all-solid-state gel electrolvte exhibits a large volume/areal capacitance of 770.72 F/cm^3(46.24 mF/cm^2)at a scan rate of 20 mV/s,a high energy density of 68.51 mWh/cm^3 at a power density of 6.16 W/cm^3,excellent cveling stability with capacitance retention of 98.50%after 10000 charge/discharge cvcles.The MSC also shows superior flexibility and stabilitv even after repetition of charge/discharge cvcles under the convex and concave bending states.In addition.the assembled MSC array(4 in series)provides a high voltage of 3.2 V,which could easily power a purple light-emitting diode more than 10 min,demonstrating its potential application in integrated portable/wearable devices.

Interfacial synthesis of crystalline quasi-two-dimensional polyaniline thin films for high-performance flexible on-chip micro-supercapacitors

Quasi-two-dimensional(q2 D)conducting polymer thin film synergizes the advantageous features of longrange molecular ordering and high intrinsic conductivity,which are promising for flexible thin film-based micro-supercapacitors(MSCs).Herein,we present the high-performance flexible MSCs based on highly ordered quasi-two-dimensional polyaniline(q2 D-PANI)thin film using surfactant monolayer assisted interfacial synthesis(SMAIS).Owing to high electrical conductivity,rich redox chemistry,and thin-film morphology,the q2 D-PANI MSCs show high volumetric specific capacitance(ca.360 F/cm^(3))and energy density(17.9 m Wh/cm^(3)),which outperform the state-of-art PANI thin-film based MSCs and promise for future flexible electronics.

利用时域整形的飞秒激光自下而上沉积多级多孔碳材料用于超高速率微型超级电容器

随着电子器件的飞速发展,微型超级电容器作为一种能快速充放电的储能装置受到了人们的广泛关注.如何在考虑能量密度的前提下进一步提高微型超级电容器的速率性能仍然是一个挑战.我们提出了一种简便的由下而上飞秒脉冲激光沉积制备薄膜的方法.利用时域整形飞秒激光通过透明基片照射聚酰亚胺薄膜,使电极材料均匀地溅射到基片的下表面,成功地沉积了性能可控的多孔非晶碳、石墨烯和碳量子点.结果表明,在10,000 V s^(-1)的扫描速率下,该微型超级电容器具有超高频响应性能.该微型超级电容器的特征频率f_(0)高达42,000 Hz,弛豫时间常数τ_(0)为0.0238 ms,在120 Hz频率下,阻抗相位角为-82.6°,同时还具有超高的功率密度(大于30 kW cm^(-3))和能量密度(0.068 W h cm^(-3)).本方法为未来小型化便携式电子器件的超高频滤波器的制备提供了新的思路.

MXenes:A comprehensive review of synthesis,properties,and progress in supercapacitor applications

MXenes,a class of two-dimensional materials,have garnered significant attention due to their unique properties and versatile applications in various fields.This review provides a comprehensive overview of MXene synthesis methods,highlighting their distinctive layered structure and tunable properties through surface functionalization.The focus then shifts to their remarkable role in supercapacitor technology.MXenes exhibit high electrical conductivity,large surface areas,and tailored surface chemistry,making them promising candidates for energy storage in supercapacitors.The paper discusses the interplay of electric double-layer capacitance and pseudocapacitance mechanisms within MXenebased electrodes,detailing recent research efforts aimed at optimizing their energy storage performance.Through a combination of theoretical insights and experimental findings,the potential of MXenes to revolutionize supercapacitor technology emerges,offering prospects for high-energy-density and long-lasting energy storage solutions.Additionally,this review highlights recent advances in MXenebased supercapacitors,including novel electrode designs,electrolyte engineering,and hybrid materials,showcasing the dynamic evolution of MXene-based supercapacitor research.This comprehensive overview aims to provide a thorough understanding of MXenes'synthesis,properties,and their pivotal role in advancing supercapacitor technology,while also encompassing the latest breakthroughs in this rapidly evolving field.