Boron and Micro-Supercapacitors

Dec 14, 2021 | ADVANCED ENERGY, Batteries and Capacitors, Energy Management

Boron and Micro-supercapacitors

Boron nitride (BN) has shown great potential for microelectronics in the architecture of micro-supercapacitors. Boron Nitride has a large bandgap (5.5eV), superior thermal stability, and high thermal conductance. Boron Micro-supercapacitors in the laboratory exhibit high energy density. They can also withstand harsh environments such as high temperature or electromagnetic interference much better than silicon-based micro capacitors. 

Boron and Micro-supercapacitors

Boron and Micro-supercapacitors

Silicon and Boron Micro-supercapacitors

With the rapid growth of digital devices, micro-supercapacitors help with power delivery for the microelectronics sector.  Micro-supercapacitors are microelectronic components that store energy and release it quickly in applications where large amounts of electric charge must be stored, such as capacitors for microcomputers or power supplies. Capacitance is the key feature that makes them suitable for microelectronics. 

However, conventional capacitors cannot store energy efficiently and thus do not function well in high-frequency systems (30 MHz) that must discharge quickly. Conversely, boron micro-supercapacitors can store and discharge much faster than conventional electrolytic capacitors, making them a suitable replacement.

With high breakdown voltage and increased capacitance, boron micro-supercapacitors are the next step in microelectronic innovation. In general, innovations are mainly driven forward by the research program Technologies for Smart Systems, in close cooperation with Materials for Micro- and Nanoelectronics.

Boron Nitride Nanotubes

Boron Nitride Nanotubes for micro-supercapacitors are up to 50% stronger than traditional steel and 10 times more elastic. Therefore, they can withstand greater strain.

Conventional thin-film micro-supercapacitors are made of a polymer and metal oxide dielectric deposited on silicon wafers or glass substrates. A thin-film micro supercapacitor can store large amounts of electric charge, while graphene micro-supercapacitors have a higher charge density. Furthermore, when using boron-doped silicon carbide thin films on silicon, efficiency can increase significantly.

Electrochemical reports show that the boron-doped silicon carbide film has a maximum capacitance value of 232F/g at 2.2A/g current densities from Galvanostatic charging and discharging methods with good cyclic stability for up to 2000 cycles. The active charge sites and surface defects can explain the high capacitance value. (B)SiC/Si can be used as an electrode material for high-performance energy storage applications.

Boron-doped Micro-supercapacitors

There are two types of micro-supercapacitors: thin-film micro supercapacitors and micro-laser induced graphene micro-supercapacitors. Both have the potential to improve microelectronics performance.

Thin Film and Micro Laser-Induced Graphene Micro-supercapacitors

Researchers at Rice’s Tour lab are creating thin, flexible supercapacitors by burning patterns into common polymers with commercial lasers. To a depth of 20 microns, the laser burns away everything except the carbon, producing a foam-like matrix of graphene flakes. The researchers first quadrupled the supercapacitor’s ability to store an electrical charge while greatly boosting its energy density by infusing the polymer with boric acid.

The micro laser-induced graphene micro-supercapacitor is an organic device that uses boron doping to achieve a higher charge density than traditional capacitors. To make boron micro-supercapacitors as efficient as possible, they must be manufactured using an epitaxial growth process with a higher charge density. Boron doped micro-supercapacitors are an integral part of microelectronic circuits and show great promise for improving their efficiency in the future.

In a collaborative research project, researchers from Korea Institute of Energy Research (KIER), Korea Advanced Institute of Science and Technology (KAIST), and Pusan National University (PNU) developed a re-attachable sticker-type energy storage device. Using highly swollen laser-induced graphene electrodes, the team developed ‘re-attachable micro-supercapacitors (MSCs).

Boron-doped Porous Carbon

A unique method for creating boron-doped porous carbon through direct carbonization used a boron-based covalent framework (COF-5). Boron oxides formed during COF-5’s carbonization could be easily removed by water treatment, which gives boron-doped porous carbon. The carbon matrix was then successfully incorporated with boron atoms. 

Supercapacitor electrodes made from the fabricated boron-doped carbon had a specific capacitance value of 15.3 mFc -2 at forty mAg -1. When the current density is the same as the traditional activated carbon electrode (6.9 mFc-2), this electrode has twice the value. Supercapacitors made from boron-doped boron showed 72% retention of capacitance after 10000 charge/discharge cycles. The new multifunctional, boron-doped COF carbon materials can be used as energy storage devices.

Boron-doped Porous Graphene

Heteroatom-doped graphene has been extensively studied for its potential as an active electrode in the energy storage device. Research shows that boron-doped porous graphene can be made in ambient air using a simple laser induction process from boric acids containing a polyimide sheet. At the same time, active electrodes can be patterned for flexible micro-supercapacitors. The highest areal capacitance for as-prepared devices is 16.5 mF/cm 2, 3 times more than non-doped, and a 5-10% increase in energy density at different power densities. This device’s remarkable cyclability and mechanical flexibility are well-maintained. This laser-induced graphene boron-doped material is a great candidate for future microelectronics.

Heteroatom doping carbon nanostructured materials are one way to increase the energy storage of supercapacitors. Graphene oxide was produced by heating under an argon atmosphere at 500°C. Boron-doped graphene sheets were prepared using hydrothermal (HB) and boric acid  (H 3BO 3). From X-ray photoelectron (XPS) studies, the atomic doping level for boron was determined as 2.56%. 

Boron Doped Graphene Nanosheets For Supercapacitor Applications

Heteroatom doping carbon nanostructured materials are one way to increase the energy storage of supercapacitors. Graphene oxide was produced by heating under an argon atmosphere at 500°C. Boron-doped graphene sheets were prepared using hydrothermal (HB) and boric acid  (H 3BO 3). From X-ray photoelectron (XPS) studies, the atomic doping level for boron was determined as 2.56%. The electric double-layer capacitance behavior of HB-GNS and T-GNS graphene nanosheets thermally reduced (CV) in Cyclic Voltammetry’s electrochemical analysis (ECA) shows the thermally reduced graphene (T-GNS).

At the same time, HB-GNS has an electronic analysis (E-AL). T-GNS had a specific capacitance value of 53 F/g (1A/g), while the HB-GNS electrode had a maximum specific capacitance (maximum specific capacitance) of 113 F/g (1A/g). The electrochemical impedance measurements show that HB-GNS has a lower Rct value than T-GNS. The specific capacitance of TGNS is twice as high as HB-GNS’s boron doping. These results indicate that HB-GNS has superior electrochemical performance due to boron doping of graphene nanosheets, high-energy storage electrode materials used for supercapacitors.

Advantages of Boron Microsupercapacitors

In conclusion, Boron Microsupercapacitors have high energy density and can withstand harsh environments such as high temperature or electromagnetic interference much better than silicon-based micro capacitors. 

Conventional capacitors cannot store energy efficiently and thus do not function well in high-frequency systems (30 MHz) that must discharge quickly. Conversely, boron micro-supercapacitors can store and discharge much faster than conventional electrolytic capacitors, making them a suitable replacement.

With their high breakdown voltage and increased capacitance, these micro-supercapacitors are the next step in microelectronic innovation. In general, innovations are mainly driven forward by the research program Technologies for Smart Systems, in close cooperation with Materials for Micro- and Nanoelectronics.