A piezoelectric nanogenerator promotes highly stretchable and self-chargeable supercapacitors

Abstract

Stretchable and piezoelectrically self-chargeable supercapacitor designed by sandwiching piezo-electrolyte shows high efficiency of energy collection, conversion, and self-charging, either under continuous slight palm patting or repeated stretching.

Recent advances in highly integrated energy conversion and storage system

“…After that, different electrode materials (e.g., carbon nanotubes, graphene, carbon cloth, MoSe 2 , NicO 2 O 4 @ activated carbon cloth, NiCoOH-CuO@Cu foil, Co-Fe 2 O 3 @carbon cloth), electrolytes containing water electrolyte gel and ionic liquid electrolyte, piezoelectric materials including porous or electrospinning PVDF, BaTiO 3 , K 0.5 Na 0.5 NbO 3 , perforated swim bladder, are used to prepare self-charging supercapacitors with symmetric or asymmetric electrodes configuration. [69][70][71][72][73][74][75][76][77] Notably, although these studies demonstrate the feasibility of self-charging behavior to some extent, further experimental data on energy conversion and storage mechanisms are still lacking, which limits the improvement of energy conversion efficiency. To better explore the mechanism of the self-charging process, Kim et al directly detected the piezoelectric electrochemical effect in the self-charging process of supercapacitor by piezoelectrochemical spectroscopy.…”

“…To achieve a new chemical equilibrium, the redox reaction will occur on the surface of the positive and negative electrodes, thus, realizing the electrical energy storage process. After that, different electrode materials (e.g., carbon nanotubes, graphene, carbon cloth, MoSe 2 , NicO 2 O 4 @ activated carbon cloth, NiCoOH‐CuO@Cu foil, Co‐Fe 2 O 3 @carbon cloth), electrolytes containing water electrolyte gel and ionic liquid electrolyte, piezoelectric materials including porous or electrospinning PVDF, BaTiO 3 , K 0.5 Na 0.5 NbO 3 , perforated swim bladder, are used to prepare self‐charging supercapacitors with symmetric or asymmetric electrodes configuration 69–77 . Notably, although these studies demonstrate the feasibility of self‐charging behavior to some extent, further experimental data on energy conversion and storage mechanisms are still lacking, which limits the improvement of energy conversion efficiency.…”

2D Nanomaterials for Effective Energy Scavenging

“…The self-charging mechanism lies in the piezo-electrochemical conversion process, which can be understood with piezo-electrochemical spectroscopic measurements [ 127 ]. The introduction of the self-charging mechanism has led to the fabrication of a self-chargeable flexible solid-state supercapacitor (FSSSC) [ 128 ], a self-charging sodium-ion battery [ 129 ], and a highly stretchable self-chargeable supercapacitor [ 130 ], which facilitates opportunities to develop wearable and flexible electronic devices that can be charged without any external power sources. Recent developments in self-charging supercapacitor-based power cells have proven to be more effective in finding a higher charging voltage, such as a porous PVDF device with a specific device capacitance of 31.63 mF cm −2 [ 124 ].…”

Self-charging power system for distributed energy: beyond the energy storage unit

“…32 This type of piezo-electrochemical process has also been demonstrated to be applicable to electrochemical double layer (EDL) supercapacitors ( Fig. 2b), [33][34][35][36][37] pseudocapacitive supercapacitors, 31,[38][39][40][41][42] and sodium ion batteries. 25 Wang et al provided a density functional theory (DFT) simulation to understand the mechanism of the piezo-electrochemical process in this type of SCPS ( Fig.…”

“…Aer applying repeated mechanical pressure of 34 N at 1 Hz for 500 s, the voltage of the Li-ion battery increased from 500 mV to 832 mV, which could deliver a discharge capacity of 0.266 mA h. 21 Flexible SCPSs also made it viable to convert mechanical input of bending and stretching into electrochemical responses. 22,23 Composite piezo-separators incorporated with inorganic piezoelectric materials with a higher piezoelectric coefficient were also investigated to improve the performances, such as lead zirconate titanate (PZT), 24 potassium sodium niobite (KNN), 23,25 NaNbO 3 , 26 0.5(Ba 0.7 Ca 0.3 )TiO 3 -0.5Ba(Zr 0.2 Ti 0.8 )O 3 (BCT-BZT) nanobers, 27 and ZnO. [28][29][30] Self-polarized piezoelectric biomaterials, e.g.…”