Sandwiched Polymer Nanocomposites Reinforced by Two‐Dimensional Interface Nanocoating for Ultrahigh Energy Storage Performance at Elevated Temperatures

Abstract

Polymer‐based dielectrics are essential components in electrical and power electronic systems for high power density storage and conversion. A mounting challenge for polymer dielectrics is how to maintain their electrical insulation at not only high electric fields but also elevated temperatures, in order to meet the growing needs for renewable energies and grand electrifications. Here, a sandwiched barium titanate/polyamideimide nanocomposite with reinforced interfaces via two‐dimensional nanocoatings is presented. It is demonstrated that boron nitride and montmorillonite nanocoatings can block and dissipate injected charges, respectively, to present a synergetic effect on the suppression of conduction loss and the enhancement of breakdown strength. Ultrahigh energy densities of 2.6, 1.8, and 1.0 J cm−3 are obtained at 150 °C, 200 °C, and 250 °C, respectively, with a charge‐discharge efficiency >90%, far outperforming the state‐of‐the‐art high‐temperature polymer dielectrics. Cyclic charge‐discharge tests up to 10 000 times verify the excellent lifetime of the interface‐reinforced sandwiched polymer nanocomposite. This work provides a new pathway to design high‐performance polymer dielectrics for high‐temperature energy storage via interfacial engineering.

Constructing asymmetric gradient structures to enhance the energy storage performance of PEI-based composite dielectrics

“…In addition, the U e of the AIG (2/1) composite dielectric can reach 4.78 J cm −3 at 150 °C, which is much higher than those of the dielectrics reported in previous studies. 42–45 When compared with pure PEI in the same electric field (240 MV m −1 ), the U e and η of the AIG (2/1) composite dielectric can reach 1.54 J cm −3 and 78.4%, respectively, which are significantly higher than those of pure PEI (1.03 J cm −3 and 52.4%). By using a simple preparation strategy of alternate electrospinning process, the distribution characteristics of BNNSs can be regulated to achieve higher breakdown strength and energy storage performances at room temperature and high temperature without additional interface modification or processing technology.…”

Scalable High‐Permittivity Polyimide Copolymer with Ultrahigh High‐Temperature Capacitive Performance Enabled by Molecular Engineering

“…It should be noted that the copolymer films are only synthesized using conventional commercial monomers. Compared with the other high temperature polymers by using external components, such as making nanocomposites or multi-layer structures, [5,15,17,23,41,43,53,[57][58][59][60][61][62][63][64][65][66] the flexible copolymer film is compatible with the industrial production line of current commercial polymer films and has the potential to be applied in hightemperature environments of electric vehicles, power electronics, and other systems.…”

“…[ 10,14 ] In contrast, aromatic polymers such as polyimide (PI) and polyetherimide (PEI) have relatively high T g (>210 °C), while the strong π–π stacking effect of its conjugated planar segments sacrifices E g (<3.2 eV), resulting in an inevitable decrease in high‐temperature capacitive performance. [ 10,15–17 ]…”

“…[10,14] In contrast, aromatic polymers such as polyimide (PI) and polyetherimide (PEI) have relatively high T g (>210 °C), while the strong 𝜋-𝜋 stacking effect of its conjugated planar segments sacrifices E g (<3.2 eV), resulting in an inevitable decrease in high-temperature capacitive performance. [10,[15][16][17] Introducing appropriate amounts of inorganic components, such as aluminum oxide (Al 2 O 3 ), magnesium oxide (MgO), boron nitride (BNNS), and hydroxyapatite) (HAP), is an effective strategy to improve the high-temperature capacitive performance of polymer dielectrics. [5,[17][18][19] Unfortunately, the common issue of filler aggregation sacrifices the flexibility, uniformity, and processability of polymer films and increases the cost of large-scale film production.…”

High thermal conductivity insulating AlN/poly(m-phenylenedicarbonyl-m-phenylenediamine) paper realized by enhanced compatibility: a selection of appropriate coupling agent

“…In order to access the goal of carbon neutrality, the revolution of future energy structure involves not only a low carbon emission level but also an electrical equipment innovation [1]. The insulating material, as a core component of the power equipment, directly affects the equipment's safety at work, which is a primary engineering challenge [2]. Poly(m-phenylenedicarbonyl-m-phenylenediamine) (PMIA) is endowed with superior insulating properties, flame retardant properties, and corrosion resistance, which is a potential candidate as the insulating paper for industrial production [3].…”