Recent progress and challenges in interdigital microbatteries:Fabrication, functionalization and integration

Currently,the increasing demands for portable,implantable,and wearable electronics have triggered the interest in miniaturized energy storage devices.Different from conventional energy storage devices,interdigital microbatteries(IMBs) are free of separators and prepared on a single substrate,potentially achieving a short ionic diffusion path and better performance.Meanwhile,they can be easily fabricated and integrated into on-chip miniaturized electronics,holding the promise to provide long-lasting power for advanced microelectronic devices.To date,while many seminal works have been reviewed the topic of microbatteries,there is no work that systematically summarizes the development of IMBs of high energy density and stable voltage platforms from fabrication,functionalization to integration.The current review focuses on the most recent progress in IMBs,discussing advanced micromachining techniques with compatible features to construct high-performance IMBs with smart functions and intelligent integrated systems.The future opportunities and challenges of IMBs are also highlighted,calling for more efforts in this dynamic and fast-growing research field.

Advanced architecture designs towards high-performance 3D microbatteries

Rechargeable microbatteries are important power supplies for microelectronic devices.Two essential targets for rechargeable microbatteries are high output energy and minimal footprint areas.In addition to the development of new high-performance electrode materials,the device configurations of microbatteries also play an important role in enhancing the output energy and miniaturizing the footprint area.To make a clear vision on the design principle of rechargeable microbatteries,we firstly summarize the typical configurations of microbatteries.The advantages of different configurations are thoroughly discussed from the aspects of fabrication technologies and material engineering.Towards the high energy output at a minimal footprint area,a revolutionary design for microbatteries is of great importance.In this perspective,we review the progress of fabricating microbatteries based on the rolled-up nanotechnology,a derivative origami technology.Finally,we discussed the challenges and perspectives in the device design and materials optimization.

Flexible and tailorable quasi‐solid‐state rechargeable Ag/Zn microbatteries with high performance

The recent boom in flexible and wearable electronics requires their powersources not only to be adequately compact but also could undergo extremedeformation without significant degradation in performance. Here, flexibleand tailorable quasi‐solid‐state microsized Ag/Zn batteries (micro‐AZBs)were designed by combining mask‐assisted spray printing and electrochemicaldeposition strategies. The micro‐AZBs display ultrastable outputvoltage, excellent energy, and power densities, as well as stable cycling performance.Furthermore, the micro‐AZBs with desired shapes can be designedin series or in parallel on a flexible chip to output improved voltage or currentwith the internal connection. More importantly, the microelectrodes could besprayed on various substrates. Flexible micro‐AZBs could be achieved onflexible substrates and tailorable micro‐AZBs are obtained when they arefabricated on clothes. They exhibit stable electrochemical performance evenunder bending or cutting states. The novel design of such quasi‐solid‐statemicro‐AZBs would pave a way for the miniaturization and integration ofenergy storage devices.

Hierarchical TiO2-B nanowire@α-Fe2O3 nanothorn core-branch arrays as superior electrodes for lithium-ion microbatteries

This paper reports a simple yet efficient method for the synthesis of hierarchical TiO2-B nanowire@α-Fe2O3 nanothorn core-branch arrays based on a stepwise hydrothermal approach. The as-fabricated hybrid arrays show impressive performance as a high-capacity anode for lithium-ion batteries. The key design in this study is a core-branch hybrid architecture, which not only provides large surface active sites for lithium ion insertion/extraction, but also enables fast charge transport owing to the reduced diffusion paths for both electrons and lithium ions. The peculiar combination of attributes of TiO2 （good structural stability） and Fe2O3 （large specific capacity） provides the hybrid array electrodes with several desirable electrochemical features： large reversible capacity （-800 mA.h.g^-1 for specific mass capacity and -750 μA.h-cm^-2 for specific areal＂ capacity）, good cycling stability, and high rate capability. The impressive electrochemical performance, together with the facile synthesis procedure, may provide an efficient platform to integrate the TiO2 nanowire@Fe2O3 nanothorn core-branch arrays as a three-dimensional thin film electrode for lithium-ion microbatteries.

Ultrahigh-energy and-power aqueous rechargeable zinc-ion microbatteries based on highly cation-compatible vanadium oxides

Aqueous multivalent-metal-ion intercalation chemistries hold genuine promise to develop safe and powerful microbatteries for potential use in many miniaturized electronics.However,their development is beset by state-of-the-art electrode materials having practical capacities far below their theoretical values.Here we demonstrate that high compatibility between layered transition-metal oxide hosts and hydrated cation guests substantially boost their multi-electron-redox reactions to offer higher capacities and rate capability,based on typical bipolar vanadium oxides preintercalated with hydrated cations(M_(x)V_(2)O_(5)).When seamlessly integrated on Au current microcollectors with a three-dimensional bicontinuous nanoporous architecture that offers high pathways of electron transfer and ion transport,the constituent Zn_(x)V_(2)O_(5) exhibits specific capacity of as high as∼527 mAh g^(−1) at 5 mV s^(−1) and retains∼300 mAh g^(−1) at 200 mV s^(−1) in 1 M ZnSO_(4) aqueous electrolyte,outperforming the M_(x)V_(2)O_(5)(M=Li,Na,K,Mg).This allows aqueous rechargeable zinc-ion microbatteries constructed with symmetric nanoporous Zn_(x)V_(2)O_(5)/Au interdigital microelectrodes as anode and cathode to show high-density energy of∼358 mWh cm^(−3)(a value that is forty-fold higher than that of 4 V/500μAh Li thin film battery)at high levels of power delivery.

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.

A betavoltaic microbattery based on PIN diodes

A betavohaic Microbattery was studied. The diode was composed of a PIN structure with an active area of 10 mm × 10 mm to collect the charge from a 10mCi Ni-63 source. An open circuit voltage of 0. 16 V and a short circuit current density of 67.6 nA/cm2 were measured. An efficiency （η） of 1.44% was obtained. The performance of device was limited by high series resistance, edge recombination and attenuation of electron in PIN diodes. It is expected to be improved by optimizing the design and using more suitable radioisotope.

High-areal-capacity/power lithium metal microbattery configuration based on the mechanically flexible,ultra-lightweight,nanocellulose framework

The ubiquitous implementation of integrated microelectronics requires the on-chip power sources featured with the lightweight configuration design,high areal-capacity-loadings as well as facile reaction kinetics that beyond the current available microbattery prototypes.Herein,this study constructs a mechanically flexible,nanocellulose fiber(NCF)reinforced microbattery configuration,which consists of metal-organic frameworks(ZIF-8)modified NCF as the separator(MOF@NCF),the carbonized MOF@NCF as the metallic deposition substrate(c-MOF@NCF)as well as gradient-structured LiFePO4 particles infiltrated in the NCF matrix(LFP@NCF)as the cathode.The film-stacked,integrated NCF-based microbattery prototype not only achieves the facile reaction kinetics with homogenized,dendrite-free Li metal deposition at high-capacity-loadings(2 mAh·cm^(-2)),but also eliminates the necessary use of metallic current collector to maximize the electroactive mass ratio,which therefore enables the high energy density of 6.8 mWh·cm^(-2)at the power output of 1.36 mW·cm^(-2)as well as the robust cyclability upon various geometric flexing states.This study presents a quantum leap towards the facile reaction kinetics and multi-scale interfacial stability for the flexible microbattery construction that based on the sustainable utilization of bio-scaffolds.

Zinc micro-energy storage devices powering microsystems

The increasing popularity of the Internet of Things and the growing microelectronics market have led to a heightened demand for microscale energy storage devices,such as microbatteries and microsupercapacitors.Although lithium microbatteries have dominated the market,safety concerns arising from incidents like self-ignition and explosions have prompted a shift towards new microscale energy storage devices prioritizing high safety.Zinc-based micro-energy storage devices(ZMSDs),known for their high safety,low cost,and favorable electrochemical performance,are emerging as promising alternatives to lithium microbatteries.However,challenges persist in the fabrication of microelectrodes,electrolyte infusion,device packaging,and integration with microelectronics.Despite these challenges,significant progress has been made over the last decade.This review focuses on the challenges and recent advancements in zinc-based micro-energy storage,offering unique insights into their applications and paving the way for the commercial deployment of high-performance ZMSDs.

Integration of all-printed zinc ion microbattery and glucose sensor toward onsite quick detections

Rational design of microsystems and efficient integration of various functional modules that can directly realize the aimed functions are very attractive for portable and onsite practical applications,which is also significant in developing miniaturized and intelligent electronics and equipment.Unlike the conventional electrochemical glucose sensors that always need auxiliary complex systems for power supply,signal processing,and feedbacks,we design an all-printed glucose sensor integrated with a zinc ion microbattery(ZIMB)as a micropower source for portable and onsite quick glucose detections.The integrated glucose sensor(GS)and ZIMB(iGS-ZIMB)systempossesses a high areal energy density of 247.3μWh/cm^(2) and power density of 1193μW/cm^(2) and exhibits high sensitivity up to 464.2μA/mM/cm^(2),wide linear range of 0.5-6.0 mM,and good reproducibility in glucose detections.Through a simple amplification circuit design,the glucose concentration signals could be displayed within a short response time of 1.6 s without the need of external auxiliary equipment.Such iGS-ZIMB microsystem has prominent advantages in efficiency and cost and is promising for onsite medical and healthcare applications.

Optimization and temperature effects on sandwich betavoltaic microbattery

The design scheme of a sandwich-structure betavoltaic microbattery based on silicon using63Ni is presented in this paper.This structure differs from a monolayer energy conversion unit.The optimization of various physical parameters and the effects of temperature on the microbattery were studied through MCNP.For the proposed optimization design,P-type silicon was used as the substrate for the betavoltaic microbattery.Based on the proposed theory,a sandwich microbattery with a shallow junction was fabricated.The temperature dependence of the device was also measured.The open-circuit voltaic(Voc)temperature dependence of the optimized sandwich betavoltaic microbattery was linear.However,the Voc of the betavoltaic microbattery with a high-resistance substrate exponentially decreased over the range of room temperature in the experiment and simulation.In addition,the sandwich betavoltaic microbattery offered higher power than the monolayer betavoltaic one.The results of this paper provide a significant technical reference for optimizing the design and studying temperature effects on betavoltaics of the same type.