Environmental energy harvesting via phase separation in conductive polymers

Abstract

Described are compositions, methods, and devices to harvest and store diffusive environmental energy to generate high power by inducing the controlled phase separation in energy harvesters comprising a first polymer system comprising a conductive polymer and a second polymer system comprising a polyanionic polymer, such as PEDOT:PSS gels.

Description

[0001] Attorney Docket No. 10046-658W01

[0002] ENVIRONMENTAL ENERGY HARVESTING VIA PHASE SEPARATION IN CONDUCTIVE POLYMERS CROSS REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority to U. S. Provisional Application No.

[0004] 63 / 711,915, filed October 25, 2024, which is incorporated by reference herein in its entirety.

[0005] BACKGROUND

[0006] Various power generation technologies have been developed to harvest diffusive energy from natural processes, such as waving (Zhao, F. et al. Materials for solar-powered water evaporation. Nat. Rev. Mater. 5, 388-401, (2020); Pei, W. et al. Waving potential at volt level by a pair of graphene sheets. Nano Energy 60, 656-660, (2019)), water evaporation (Xue, G. et al. Water-evaporation-induced electricity with nanostructured carbon materials. Nat. Nanotechnol. 12, 317-321, (2017); Hu, Q., et al. Hydrovoltaic electricity generation induced by living leaf transpiration. Nat. Water 2, 988-998 (2024)), and moisture diffusion (Wang, H., et al. Moisture adsorption-desorption full cycle power generation. Nat. Commun.

[0007] 13, 2524 (2022); Wang, H. et al. Bilayer of polyelectrolyte films for spontaneous power generation in air up to an integrated 1,000 V output. Nat. Nanotechnol. 16, 811-819, (2021)). Despite the successful demos, one common intrinsic drawback in current technologies is that the extraction of the above-mentioned energy requires constant external stimuli. Wherein, the power supply is limited by weather or geological conditions as the output power is heavily dependent on the input power (e.g., flowing, droplet speed). Therefore, developing further energy harvesting technology via exploring materials capable of harvesting, concentrating, and storing diffuse environmental energy is desired to extend the application scenarios of power generation with higher performance. Energy storage typically requires materials to have different steady states after energy harvesting. Conductive polymers (CPs), commonly used with various ionic dopants, provide a unique platform for mixed ionic-electronic transport, which can be manipulated into multi-level steady states through phase separation between the electronically conductive phase and the ionically conductive phase (Rivnay, J. et al. Structural control of mixed ionic and electronic transport in conducting polymers. Nat. Commun. 7, 11287, (2016); Yuk, H., Lu, B. & Zhao, X. Hydrogel bioelectronics. Chem. Soc. Rev. 48, 1642-1667, (2019); Guo, Y. et al. Hydrogels and hydrogel-derived materials for energy and water sustainability. Chem. Rev. 120, 7642-7707, (2020); Balakrishnan, G., Song, J., Mou, C. & Bettinger, C. J. Recent Progress in Materials Chemistry to Advance Flexible Bioelectronics in Medicine. Adv. Mater. 34, 2106787, (2022); Shi, Y., et al. Nanostructured conductive polymers for advanced energy storage. Chem. Soc. Rev. 44, 6684-6696, (2015)). Attorney Docket No. 10046-658W01

[0008] Considering that the movement of charge carriers is the nature of electricity generation, harvesting environmental energy to regulate the separation, distribution, and transport of the ionic and electronic charges in CPs becomes a possible way to generate power. In addition, in comparison with the existing solid electrodes used in the environmental energy harvesting field, the formation of molecular-level electrical double layer (EDL) in CPs can help yield a much higher volumetric EDL density, useful for higher power generation performance (Chen, H.-W. et al. PEDOT: Fundamentals and its nanocomposites for energy storage. Chin. J. Polym. Sci. 38, 435-448, (2020)).

[0009] SUMMARY

[0010] Disclosed are compositions, and methods of making and using thereof. In one aspect, the disclosed subject matter relates to compositions, methods, and devices to harvest and store diffusive environmental energy to generate high power by inducing the controlled phase separation in energy harvesters comprising a first polymer system comprising a conductive polymer and a second polymer system comprising a polyanionic polymer, such as PEDOT: PSS gels. In some aspects, the energy harvester can comprise an entangled polymer network comprising a first polymer system comprising a conductive polymer non-homogenously entangled with a second polymer system comprising a polyanionic polymer. In yet other aspects, the energy harvester can comprise an entangled polymer network comprising a first polymer system comprising a conductive polymer entangled with a second polymer system comprising a polyanionic polymer, wherein the conductive polymer and polyanionic polymer are phase separated. In still further aspects, the energy harvester can comprising an entangled polymer network comprising a first polymer system comprising a conductive polymer entangled with a second polymer system comprising a polyanionic polymer, wherein the entangled polymer network comprises a first portion comprising a high concentration of conductive polymer and low concentration of polyanionic polymer, and a second portion comprising alow concentration of conductive polymer and high concentration of polyanionic polymer. Also disclosed is an electrochemical cell comprising the energy harvester according to any preceding claim in electrical communication with a first electrode, a second entangled polymer network in electrical communication with a second electrode, a separator disposed between the first and second energy harvesters.

[0011] Additional advantages of the disclosed subject matter will be set forth in part in the description that follows and the figures, and in part will be obvious from the description or can be learned by practice of the aspects described below. The advantages described below will be realized and attained by means of the elements and combinations particularly pointed Attorney Docket No. 10046-658W01

[0012] out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.

[0013] BRIEF DESCRIPTION OF THE FIGURES

[0014] The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate several aspects described below.

[0015] Figures 1A and IB, Power generation based on diffuse environmental energy-driven phase separation. (FIG. 1A) Schematic illustration of the environmental energy-induced phase separation in PEDOT: PSS gel, resulting in electric power generation. Environmental energy can be harvested via dehydration of PEDOT: PSS hydrogel, which leads to phase separation. At the molecular level, this is the result of the rearrangement of molecules, which also gives rise to charge redistribution, as depicted in the middle part of the scheme where negatively charged chains refer to PSS and positively charged chains refer to PEDOT. (FIG. IB) Schematic showing power generator composed of PEDOT: PSS gels at high phase separation level (PSL) and low PSL. When immersing gels into an electrolyte, the hydrophilic PSS with negative fixed charge allows the penetration of counterions (cations), as shown in the insets (framed in blue dashed lines). The difference in charge density of high- and low-PSL gels results in a voltage difference ( ( / >). As the high-PSL gel end experienced multiple H-D cycles, the power output between gels also increases as a result of the accumulation of the harvested environment energy.

[0016] Figures 2A-2E, Characterizations of PEDOT: PSS gels in different PSLs. (FIG. 2A) AFM phase images showing the morphology of PEDOT: PSS gels in different PSLs. (FIG.

[0017] 2B) WAXS curves showing the crystallinity of PEDOT: PSS gels in different PSLs. (FIG. 2C) A schematic of the three-electrode system, consisting of Pt sheet (counter electrode), Ag / AgCI (reference electrode), and PEDOT: PSS gel (working electrode). (FIG. 2D) Illustration of the potential between PEDOT: PSS gel and Ag / AgCI. (FIG. 2E) Potentials (vs. Ag / AgCI, EAg / Agci) of PEDOT: PSS gels in different PSLs.

[0018] Figures 3A-3G, Mechanisms for electric output. (FIG. 3A) Scheme showing power generation (PG) composed of PEDOTiPSS with low (PSLO) and high (PSL5) phase separation levels. (FIG. 3B) The Vocof the PG. (FIG. 3C) Scheme diagram (top ) showing the structural difference in PEDOT: PSS with low (PSLO) and liigh (PSL5) phase separation levels. COMSOL simulation (bottom) showing the Galvani potential of each component in the PG system. < / )s,

[0019]

[0020] and (bgn are the Galvani electric potential of the electrolyte, low-PSL gel, and high-PSL gel. < / > D. H,

[0021]

[0022] are the Donnan potential of low-PSL gel and high-PSL gel. Attorney Docket No. 10046-658W01

[0023] is the potential difference between low-PSL gel and high-PSL gel. (FIG. 3D) Calculation curve and experimentally measured values of Eg / Aga vs. electrolyte concentrations of PSLO and PSL5. (FIG. 3E) EAg / Agct of PSLO and PSL5 in electrolytes with different kinds of salts. (FIG. 3F) The equivalent circuit of the PG system. (FIG. 3G) Potential difference and short circuit current between PSLO and PSL5 in NaCI electrolyte with different concentrations.

[0024] Figures 4A-4H, Power generation of PEDOT: PSS gel-based PG devices. (FIG. 4A) Scheme showing the structure of a single PG device prototype. (FIG. 4B) OCV of the single PG device prototype at different angles, showing good flexibility. (FIG. 4C) The output power density at different external resistances from a single PG device. A maximum power density of 1.27 W g can be achieved at 100 fl external resistance. (FIG. 4D) OCV of PG series device group with different numbers of series. (FIG. 4E) Digital image showing the portability of the foldable PG device and scheme of 10 PG prototypes connected in series (bottom part). (FIG. 4F) Digital image showing the (I) front view and (II) side view of the 20 foldable and portable PG devices. Scale bar is 4 cm. (FIG. 4G) Flashlight powered by 20 PG devices. Scale bar: 3 cm. (FIG. 4H) Cell phone charged by 50 PG devices. Scale bar: 3 cm.

[0025] Figure 5, Swelling behavior of PSL1-5. Swelling test results showed that the saturated water content of PEDOT: PSS gel decreases from PSL1 (11 g g-1) to PSL5 (7 g g-1), indicating that crosslinking density increases from PSL1 to PSL5.

[0026] Figures 6A-6D, Microstructure and electric potential of PSLO. (FIG. 6A) AFM phase image of PSLO. (FIG. 6B) WAXS curves of PSLO and PSL1. (FIG. 6C) Electric potential of PSLO. (FIG. 6D) XPS spectra of PH1000, PSLO, PSL1 and PSL5.

[0027] Figure 7, Composition of PEDOT: PSS gels. FTIR spectra of PH1000, PSLO, PSL1, PSL5.

[0028] Figures 8A-8C, Energy accumulation process. (FIG. 8A) Voc between PSLO and PSL1-5 at different phase separation levels in 0.6 mol L-1NaCl electrolyte solution. (FIG. 8B) Q at different phase separation levels obtained from short-circuit current experiments in 0.6 mol L-1NaCl electrolyte solution. (FIG. 8C) The Power density at different phase separation levels with external loading of 100Ω, which is an optimized resistance to produce the highest output power in 0.6 mol L-1NaCl electrolyte solution.

[0029] Figures 9A-9C, Double-layer capacitance of PSLO and PSL5. (FIG. 9A) CV curves of (FIG. 9B) PSLO and (FIG. 9C) PSL-5 at scan rates of 5, 10, 15, 20, 25 and 30 mV s’1, respectively.

[0030] Figures 10A-10I, Phase separation level of d-PSL5. (FIG. 10A) Potential of PSL5 before discharging and after discharging in 5 cycles. (FIG. 10B) WAXS of discharged PSL5 Attorney Docket No. 10046-658W01

[0031] (d-PSL5), PSL1, PSL3 and PSL5. AFM phase image of (FIG. 10C) d-PSL5, (FIG. 10D) PSL1, (FIG. 10E) PSL3 and (FIG. 10F) PSL5. (FIG. 10G) Potential of d-PSL5 during regeneration without grounding. (FIG. 10H) Potential of PSL5 during discharging and grounding in NaCl solution with grounding. (FIG. 101) Potential of d-PSL5 during regeneration with grounding.

[0032] Figures 11A-11D, Phase separation level of d-PSLO. (FIG. 11A) Potential of PSLO before discharging and after discharging in 5 cycles. (FIG. 1 IB) WAXS pattern of discharged PSLO (d-PSLO) and PSLO. AFM phase image of (FIG. 11C) d-PSLO and (FIG. 1 ID) PSLO.

[0033] Figures 12. A-12D, Flexibility of portability of PG devices. (FIG. 12A) The flexibility of the PG device. (FIGS. 12B-12C) The digital photos of wearable integrated PG devices. (FIG. 12D) Large-scale gel / fabric sample. Scale bar: (FIG. 12A), left: 3 cm; right: 2.5 cm; (FIG. 12B), 15 cm; (FIG. 12C) 5 cm; (FIG. 12D) 20 cm.

[0034] Figure 13, Analysis of short-circuit current. Short-circuit discharge curve of the PG device in 0.6 mol L1NaCl.

[0035] Figure 14, Power generation properties in different loadings. Output voltage and current density of single PG device varying with loading resistance.

[0036] Figures 15A-15B, Power generation properties in electrolytes with different concentrations. (FIG. 15A) Output voltage and current, and (FIG. 15B) power of PG device in NaCl electrolyte with different concentrations. The external resistances are 40 kfl, 7 kfl, 1.5 kfl, 200 fl, 100 fl and 50 fl for test in NaCl electrolyte with different concentrations of 0.00006mol / L, 0.0006 niol / L, 0.006 mol / L, 0.06 mol / L, 0.6 niol / L, and 6 mol / L, correspondingly. The external resistance is an optimized resistance to produce the highest output power in each NaCl electrolyte.

[0037] Figures 16A-16B, Cycling stability. Regeneration behaviors of PG device. (FIG. 16 A) Voc, (FIG. 16B) Q and peak current of PG device during cycle 1-5.

[0038] Figures 17A-17B, Comparison of performance with other power generation technologies. Summary: (FIG. 17A) Gravimetric power density and (FIG. 17B) gravimetric current density with different power generation mechanisms.

[0039] Figures 18A-18C, Demonstration of portable PG devices. (FIG. 18A) Digital image of the 50 portable PG devices. (FIGS. 18B-18C) Digital image of a 5-PG-device example showing the PG devices can be air-dried by unfolding the series device group. Scale bar: (FIG.

[0040] 18A-18B) 3 cm; (FIG. 18C) 4cm.

[0041] DETAILED DESCRIPTION

[0042] The following description of the disclosure is provided as an enabling teaching of the disclosure in its best, currently known aspects. Many modifications and other aspects Attorney Docket No. 10046-658W01

[0043] disclosed herein will come to mind to one skilled in the art to which the disclosed compositions and methods pertain, having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosures are not to be limited to the specific aspects disclosed and that modifications and other aspects are intended to be included within the scope of the appended claims. The skilled artisan will recognize many variants and adaptations of the aspects described herein. These variants and adaptations are intended to be included in the teachings of tliis disclosure and to be encompassed by the claims herein.

[0044] Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0045] As can be apparent to those of skill in the art upon reading this disclosure, each of the individual aspects described and illustrated herein has discrete components and features that may be readily separated from or combined with the features of any of the other several aspects without departing from the scope or spirit of the present disclosure.

[0046] Any recited method can be carried out in the order of events recited or in any other order that is logically possible. That is, unless otherwise expressly stated, it is in no wayintended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not specifically state in the claims or descriptions that the steps are to be limited to a specific order, it is in no way intended that an order be inferred in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to the arrangement of steps or operational flow', plain meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the specification.

[0047] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. 'The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Further, the dates of publication provided herein can be different from the actual publication dates, which can require independent confirmation.

[0048] It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed compositions and methods belong. It can be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context Attorney Docket No. 10046-658W01

[0049] of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0050] Prior to describing the various aspects of the present disclosure, the following definitions are provided and should be used unless otherwise indicated. Additional terms may be defined elsewhere in the present disclosure.

[0051] General Definitions

[0052] In this specification and in the claims that follow, reference will be made to many terms, which shall be defined to have the following meanings:

[0053] As used herein, “comprising” is to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to but does not preclude the presence or addition of one or more features, integers, steps, or components, or groups thereof. Moreover, each of the terms “by,” “comprising,” “comprises,” “comprised of,” “including,” “includes,” “included,” “involving,” “involves,” “involved,” and “such as” are used in their open, non-limiting sense and may be used interchangeably. Further, the term “comprising” is intended to include examples and aspects encompassed by the terms “consisting essentially of’ and “consisting of.” Similarly, the term “consisting essentially of’ is intended to include examples encompassed by the term “consisting of.

[0054] As used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0055] "Optional" or "optionally" means that the subsequently described event or circumstance can or cannot occur and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0056] A weight percent (wt.%) of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included.

[0057] Energy Harvester

[0058] Power generation technologies harvesting environmental energy emerge as promising power supply methods for diverse electronics applications (Liu, X. et al. Power generation from ambient humidity using protein nanowires. Nature 578, 550-554, (2020); Zhang, B., et al. Nature -inspired interfacial engineering for energy harvesting. Nat. Rev. Electr. Eng. 1, 218-233 (2024); Xu, J., et al. Sustainable moisture energy. Nat. Rev. Mater. 9, 722-737 (2024)). A series of innovative power generation mechanisms have been explored to enable harvesting the environmental energy in nature, such as water motions (Yin, J. et al. Generating electricity by moving a droplet of ionic liquid along graphene. Nat. Nanotechnol. 9, 378-383, Attorney Docket No. 10046-658W01

[0059] (2014); Xu, W. et al. A droplet-based electricity generator with high instantaneous power density. Nature 578, 392-396, (2020); Zhao, F. et al. Materials for solar-powered water evaporation. Nat. Rev. Mater. 5, 388-401, (2020); Li, L. et al. Sparking potential over 1200 V by a failing water droplet. Sci. Adv. 9, eadi2993 (2023); Xia, H., et al. Electricity generated by upstream proton diffusion in two-dimensional nanochannels. Nat. Nanotechnol.

[0060] 19, 1316-1322 (2024); Kim, S. H. et al. Harvesting electrical energy from carbon nanotube yarn twist. Science 357, 773-778, (2017)), moisture (Wang, H., et al. Moisture adsorption-desorption full cycle power generation. Nat. Commun. 13, 2524 (2022); Wang, H. et al. Bilayer of polyelectrolyte films for spontaneous power generation in air up to an integrated 1,000 V output. Nat. Nanotechnol. 16, 811-819, (2021)), and low-grade heat (Ying, P. et al. Towards tellurium-free thermoelectric modules for power generation from low-grade heat. Nat. Commun. 12, 1121, (2021); Yu, B. et al. Thermosensitive crystallization-boosted liquid thermocells for low-grade heat harvesting. Science 370, 342-346, (2020); Han, C.-G. et al. Giant thermopower of ionic gelatin near room temperature. Science 368, 1091-1098, (2020); Xue, G. et al. Water-evaporation-induced electricity with nanostructured carbon materials. Nat. Nanotechnol. 12, 317-321, (2017)). However, a lack of an energy accumulation mechanism in current technologies limits the output power. A conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) hydrogel -based power generator that can concentrate the low power density energy from the ambient environment for higher power output is disclosed. When the environmental energy triggers the dehydration of the PEDOT: PSS gel, the energy will be harvested and stored in the gel via the separation between PEDOT and PSS phases. As the hydration-dehydration cycle increases, the phase separation level enhances, with energy gradually accumulating inside the gel before reaching an equilibrium state. As a result, a high output power of up to 1270 watts per kilogram can be achieved. These findings demonstrate that the polymer chain rearrangement-induced charge separation can effectively harvest, concentrate, and store the energy from the environment, providing a new strategy for environmental energy -based power generation.

[0061] Disclosed herein, in one aspect, are energy harvesters comprising a combination of polymer systems. In one specific example, one polymer system can comprise a conductive polymer and another polymer system can comprise a polyanionic polymer. In other examples, the energy harvester can comprise an entangled polymer network comprising a first polymer system comprising a conductive polymer non-homogenously entangled with a second polymer system comprising a polyanionic polymer. In yet other examples, the energy harvester can comprise an entangled polymer network comprising a first polymer system Attorney Docket No. 10046-658W01

[0062] comprising a conductive polymer entangled with a second polymer system comprising a polyanionic polymer, wherein the conductive polymer and polyanionic polymer are phase separated. In still further examples, the energy harvester can comprising an entangled polymer network comprising a first polymer system comprising a conductive polymer entangled with a second polymer system comprising a polyanionic polymer, wherein the entangled polymer network comprises a first portion comprising a high concentration of conductive polymer and low concentration of polyanionic polymer, and a second portion comprising a low concentration of conductive polymer and high concentration of polyanionic polymer. There can be a plurality of first portions and plurality of second portions.

[0063] For example, disclosed herein is an energy harvester comprising a poly(3,4-ethylenedioxythiophene) and poly(styrenesulfonate) (PEDOT: PSS) gel. These compositions can be used to harvest environmental energy for power generation. The power generation relies on the phase separation-induced charge redistributions (see FIG. 1A in the context of a PEDOT: PSS gel), which is realized via the hydration / dehydration (H-D) cycles enabled by diffuse environmental energy. Driven by dehydration in each H-D cycle, PEDOT and PSS chains can separate from the PEDOT: PSS assemblies into the PSS-rich and PEDOT-rich domains via tt-tt stacking (Chen, H.-W. et al. PEDOT: Fundamentals and its nanocomposites for energy storage. Chin. J. Polym. Sci. 38, 435-448, (2020); Shi, H., et al. Effective approaches to improve the electrical conductivity of PEDOT: PSS: a review. Adv. Electron. Mater. 1, 1500017, (2015); Wang, Y. et al. A highly stretchable, transparent, and conductive polymer. Sci. Adv. 3, e1602076, (2017)), resulting in a gel with a higher phase separation level (PSL), thus storing the harvested environmental energy. Upon phase separation, the rearrangement of positively charged PEDOT and negatively charged PSS gives rise to charge redistribution. When hydrated by the ionic solution, the resultant difference in concentration of penetrated mobile ions leads to a change in electric potential (FIG. IB). As a result, when PEDOT: PSS gel is connecting a counter PEDOTiPSS gel electrode with a lower PSL., the stored environmental energy can be released and transformed into electric power. As environmental energy accumulates in PEDOT: PSS after multiple H-D cycles, the level of phase separation gradually and steadily increases, resulting in enhanced power output.

[0064] To investigate the energy harvesting process, PEDOT:PSS gels in different PSLs (categorized from PSL1 to PSL5) were examined. FIG. 2A shows the atomic force microscopy (AFM) phase images of these PEDOT: PSS gels, where the rigid PEDOT-rich regions (bright regions) are distributed within soft PSS matrix (dark domains) (Lu, B. et al. Pure PEDOT: PSS hydrogels. Nat. Commun. 10, 1043, (2019)). With an increase in PSL, the Attorney Docket No. 10046-658W01

[0065] PEDOT-rich regions gradually stack and grow, from a well-distributed morphology to a highly phase-separated one with clearly increased PEDOT-rich domain size. This is because, during hydration, hydrogen bonds between the solvable PSS and water are formed, while PEDOT could not be solvated (as physical crosslinking points). As the hydrogen- bonded water evaporated in the subsequent dehydration process, the hydrogen-bonding interaction occurred between sulfonate groups, leading to increased interaction between PSS chains (Zhou, J. et al. The temperature-dependent microstructure of PEDOT / PSS films: insights from morphological, mechanical and electrical analyses. J. Mater. Chem. C 2, 9903-9910, (2014)).

[0066] The degree of phase separation can also be reflected by evolution in crystallinity. Figure 2B shows the changes in wide-angle X-ray scattering (WAXS) as multiple H-D cycles proceed. All gels share two common peaks at q= ~1.85 Å-1and q = ~1.22 Å-1, corresponding to the (010) of PEDOT and the PSS amorphous scattering, respectively (Kim, S.-M. et al. Influence of PEDOT: PSS crystallinity and composition on electrochemical transistor performance and long-term stability. Nat. Commun. 9, 3858, (2018)). From PSL1 to PSL5, an obvious enhancement in peak intensity of (010) is observed, indicating a higher degree of aggregate ordering. Besides, the peak at q = ~0.38 Å-1that comes from (100) peak of PEDOT also shows increasing intensity from PSL1 to PSL5. The increase in ordering agrees well with the AFM results. In addition, the swelling behavior showing a decreasing saturated water content also reflects that crosslinking density increased from PSL1 to PSL5 (FIG. 5), which originated from the more aggregated PEDOT domain matrix.

[0067] To verify the assumption that charge is redistributed in PEDOT: PSS gel generated by phase separation, the electric potential of gels was monitored in different PSLs in a three-electrode system with a platinum counter electrode, Ag / AgCl as the reference electrode, and 0.6 mol L-1NaCl as the electrolyte (FIG. 2C). For PEDOT: PSS gels immersing in an ionic solution, the diffusion of ion from bulk solution to gel is controlled by the charge in PEDOT: PSS, in which the resultant electric potential can change in the charge distribution (FIG. 2D). Figure 2E shows that PEDOT: PSS gels induced different electric potentials (vs. Ag / AgCI, EAg / Agci) in which the measured average EAg / AgClfrom PSL1 to PSL5 are 0.334V, 0.302V, 0.270V, 0.238V, 0.200V, with corresponding H-D cycles are summarized in Table 1. Taken together, these results indicate that as the level of phase separation increases, the EAg / AgClof gels decreases.

[0068] With the establishment of the relationship between electric potential and the PSL, a large PSL difference is desired between two PEDOT: PSS electrodes for a high-performance Attorney Docket No. 10046-658W01

[0069] power generation (PG) device. Therefore, using a different gelation strategy, a PEDOT: PSS gel was fabricated with a lower PSL than PSL 1-5, as evidenced by AFM (FIG. 6A) and WAXS results (FIG. 6B). The average electric potential versus Ag / AgCl of the gel is 0.525V (FIG. 6C). This gel is thus named PSLO. X-ray photoelectron spectroscopy (XI’S) results indicate that the ratio of PSS in PSLO is close to that in pure PEDOT: PSS film made by directly drying PH1000, i.e., the PEDOT: PSS dispersion, while PSL1 and PSL5 have a lower PSS ratio, exhibiting the higher PSL due to the removal of PSS (FIG. 6D). Fourier-transform infrared spectroscopy (FI’IR) experiments reveal that PSL0-5 are pure PEDOT: PSS gels without other components (FIG. 7), again indicating that such structural difference is key for electric potential change.

[0070] Thus, disclosed herein, in one aspect, energy harvesters comprising a first polymer system comprising a conductive polymer and a second polymer system comprising a polyanionic polymer. Examples of suitable conductive polymers include a poly( thiophene), poly (aniline), poly (pyrrole), poly(carbazole), poly(azepine), polyphenylene sulfide, and any combination thereof. In a specific example, the conductive polymer has the formula:

[0071]

[0072] wherein X is S, O, or NR, wherein R is H or C1-4alkyl, R1and R2are independently chosen from H, C1-6alkyl, C1-6alkoxy, C1-6haloalkyl, C1-6haloalkoxy, F, Cl, Br, I, CN, NO2, and wherein R1and R2, together with the two carbons to which they are attached, may form a five, six, or seven member ring. In some specific examples, X is S, and R1and R2together form a six or seven member ring, wherein said ring optionally has two oxygen atoms.

[0073] Examples of suitable polyanionic polymers include a poly-carboxylic acid, a polysulfonic acid, a poly-phosphonic acid, and any combination thereof. In specific examples, the polyanionic polymer comprises a polytacrylic acid), poly(methacrylic acid), poly(2-acrylamido-2-methyl-1-propanesulfonic acid), polystyrene sulfonic acid, polyvinyl sulfonic acid, polyvinylphosphonic acid, or a combination thereof.

[0074] In some examples, the conductive polymer and the polyanionic polymer are present in a wt.% ratio from 5:1 to 1:5, 5:1 to 1:1, from 5:1 to 2.5:1 from 4:1 to 2:1, from 2.5:1 to 1:2.5, from 2.5:1 to 1:1, from 1.5:1 to 1:1.5, from 1.5:1 to 1:1, from 1:1 to 1:1.5, from 1:1 to Attorney Docket No. 10046-658W01

[0075] 1:2.5, from 1:2 to 1:4, from 1:2.5 to 1:5, or from 1:1 to 1:5, preferably from 1:2 to 1:4, or 1:2.5.

[0076] The disclosed energy harvesters can also comprise an aqueous solution comprising dissolved salts, for example, at a concentration from 0.1-4 M, from 0.1-3 M, from 0.1-2 M, from 0.1-2M, from 0.1-1.5 M, from 0.1-1 M, from 0.25 -IM, from 0.5 -IM, or from 1-2M. In some examples, the aqueous solution comprises river water (including stream, creek, etc), rainwater, lake water, non-potable water, wastewater, ocean water, or a combination thereof.

[0077] The disclosed energy harvesters can exhibit a lower electric potential than the otherwise same entangled polymer network that is not non-homogenously distributed, does not include a first and second portion, does not have phase separation, measured vs. Ag / AgCl under the same conditions. The disclosed energy harvesters can exhibit a lower electric potential than the otherwise same entangled polymer network that is not non-homogenously distributed, does not include a first and second portion, does not have phase separation, measured vs. Ag / AgCl under the same conditions.

[0078] Methods of Use

[0079] Also disclosed are methods of using the disclosed energy harvesters to harvest environmental energy. Thus, disclosed in another aspect, is a method of harvesting environmental energy, comprising subjecting an energy harvester to one or more hydration / dehydration cycles, wherein the energy harvester comprises a first polymer system comprising a conductive polymer and a second polymer system comprising a polyanionic polymer. The energy harvesters, conductive polymers, polyanionic polymers, and aqueous solution can be any of the ones disclosed herein. In some examples, the hydration / dehydration cycle comprises contacting the harvester with an aqueous solution for a first period of time to form a hydrated harvester, and then exposing the hydrated harvester to dehydrative conditions for a second period of time to form a dehydrated harvester. The first period of time can be from 0.1-100 minutes, from 0.1-50 minutes, from 0.1-25 minutes, from 0.1-10 minutes, from 0.1-5 minutes, from 0.1-2 minutes, or from 0.1-1 minute. The dehydration conditions can comprise, for example, air drying, exposure to sunlight, exposure to thermal energy, or a combination thereof. The dehydrative conditions can reduce the water content in the hydrated energy harvester by at least 40 wt.%, at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 85 wt.%, at least 90 wt.%, or at least 95 wt.%.

[0080] The energy harvester can be subjected to at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 hydration / dehydration cycles. For example, Attorney Docket No. 10046-658W01

[0081] the energy harvester can be subjected to 2, 3, 4, 5, 6, 7, 8, 9, or 10 hydration / dehydration cycles.

[0082] Power Generation Device

[0083] A PG device can be constructed between PSLO and ahigh-PSL PEDOT: PSS gel (FIG.

[0084] 3A). As the PSL of the high-PSL electrode increases from PSL1 to PSL5, the PG device presents a gradually increasing voltage, Q, and power, showing the cumulative environmental energy harvesting (FIGS. 8A-8C). A PG device consisting of PSLO and PSL5 thus presents a constant voltage of 0.34V (FIG. 3B). To understand the potential difference caused by the PSL difference, the Donnan potential model can be viewed. When an ion-impenetrable surface, which is covered by an ion-penetrable charged layer (e.g., polyelectrolyte), is in contact with an ionic solution, the mobile ions will diffuse into the charged layer due to concentration difference. Mainly attracting counterions, the charged layer induces a concentration gradient of mobile ions across the charged layer and solution, hence leading to an electric potential difference between the ion-impenetrable surface and the ionic solution, known as Donnan potential (Gokturk, P. A. et al. The Donnan potential revealed. Nat. Commun. 13, 5880, (2022); Ohshima, H. Theory of electrostatics and electrokinetics of soft particles. Sci. Technol. Adv. Mater. 10, 063001, (2009)). Specific to the present disclosure, the negatively charged PSS in PEDOT: PSS gel facilitates the migration of cations (Romele, P., et al. Ion buffering and interface charge enable high performance electronics with organic electrochemical transistors. Nat. Commun. 10, 3044, (2019)), enabling Donnan potential, between the PEDOT-rich domain and the bulk electrolyte, which can be described by Equation (1) (Guo, H. et al. Quantitative observation of electric potential distribution of brittle poly electrolyte hydrogels using microelec trode technique. Macromolecules 49, 3100-3108, (2016))

[0085]

[0086] where R, T, F are the gas constant, temperature, and Faraday constant, respectively. Equation (1) suggests that is determined by the fixed charge density of PSS, electrolyte concentration co, and valency of the mobile cation zm. As shown in the COMSOL results in Figure 3C, with the same co and Zm in one electrolyte, of gel in PSL5 φ(L) is lower than that of gel in PSL1 φ(H), which comes from the different cy. In gel at a low PSL, the majority of PEDOT and PSS exist as well-blended, electro neutral PEDOT: PSS. The phase separation induces the dissociation of PSS ions from PEDOT, with the dissociated PEDOT chains Attorney Docket No. 10046-658W01

[0087] forming larger crystalline and the more compact PSS providing more fixed negative charges. Therefore, PEDOT: PSS gel at higher PSL has higher c, thus resulting in lower < / > D.

[0088] Ag / AgCl electrode was applied to measure the electric potential of PSLO and PSL5, as the < / > D of a gel in electrolyte solution cannot be accurately measured. Figure 3D shows that the EAg / Agci of both PSLO and PSL5 increase as the concentration of electrolyte increases, which fit well with the simulation results based on Equation 1 that

[0089]

[0090] increases with co, implying that the generation of potential difference between gels in different PSLs can be explained by the proposed mechanism. Furthermore, the potential of PSLO and PSL5 were tested in electrolytes with different cations at the same salt concentration (FIG. 3E). 'The results demonstrate that a higher valency cation will lead to a higher EAg / AgCl, which also agrees well with the trend predicted by the proposed model φDincreases with zm.

[0091] Considering the EDL formed between PSLO / electrolyte and PSL5 / electrolyte as capacitors CL and CH, respectively, the equivalent electrical circuit of the system can be described as shown in Figure 3F, where RE represents the resistances across the electrolyte. Compared with CL, CH has a larger capacitance due to the higher potential difference with the solution, further evidenced by the measurement of double-layer capacitance (FIGS. 9A-9C). Upon closing the external circuit, charge transfer will occur as long as there is a potential difference, A^, between the two gel electrodes. For convenience, the equivalent circuit of the system can be further simplified to a current source I, as shown in the bottom part of Figure 3F. Measurements of potential difference and short-circuit current between PSLO and PSL5 were conducted with electrolyte concentration spanning five orders of magnitude from 0.00006 mol L’1to 6 mol L1(FIG. 3E). No notable difference

[0092]

[0093] was observed in this large concentration range, consistent with the prediction of Equation (1 ). On the contrary, an increase in short-circuit current with concentration was observed, resulting from the decrease in RE while A^ remained nearly the same (Equation S5), which is in agreement with the proposed circuit model. The state of phase separation of discharged PSLO (d-PSLO) and discharged PSL5 (d-PSL5) was also examined, where charge distribution was changed compared to PSLO and PSL5, respectively. The good agreement between the obtained electric potentials and phase separation levels of both d-PSLO and d-PSL5 lends additional support to the proposed model (FIGS. 10A-10I and FIGS. 11A-11D).

[0094] According to the phase-separation-induced voltage mechanism, a PG device comprising of PSL5- and PSLO-coated fabric electrodes is demonstrated. As shown in Figure 4A, a separator was sandwiched between the PSL5 / fabric electrode and PSLO / fabric counter electrode, and the whole PG device was encapsulated with hydrophobic fabric. Note that two Attorney Docket No. 10046-658W01

[0095] carbon cloth strips coated by gold were used as current collectors to achieve ohmic contact here. The as-assembled device (10x7 cm2in dimensions) was highly robust and flexible (FIG.

[0096] 12A-12C. Benefiting from the simple solution-based loading process (Methods), the PSL5 / fabric (PSLO / fabric) electrode can be easily patterned into different sizes for various application scenarios. A large-scale PEDOT: PSS gel-based fabric electrode with a size of about 80 cmx50 cm is prepared (FIG. 12D).

[0097] The power generation properties of the PG device was investigated. Upon immersing the device in 0.6 mol L NaCl, a stable Voc of c.a. 0.34 V can be immediately generated between two electrodes due to the rapid formation of (bDalong with the hydration of PEDOT: PSS. The Voc curves showed a negligible change at various bending angles of the PG device ranging from 0 to 360°(FIG. 4B), indicative of an excellent mechanical and electronic conductivity stability. Analysis of short-circuit current further demonstrated that a record-high peak current density exceeding 18.1 A g’1can be achieved (FIG. 13). Figure 4C shows the output power (P) of a single device with different external resistances, which can be calculated by P = 1 x U, where I is the peak current density and U is the voltage across the load (FIG. 14). The maximum output power reaches up to 1.27 W g’!at an optimal load resistance of 100 Ω. Power densities in different electrolyte concentrations (0.00006 - 6 mol L’1) were also investigated and increased. As the electrolyte concentrations increased, higher power density was obtained due to higher current density brought by the lower resistance in the electrolyte (FIGS. 15A-15B). After discharge, the PG device can be successfully recharged without obvious performance decay (FIGS. 16A-16B). Benefiting from the phase separation-induced voltage and molecular-level EDL, PEDOT: PSS-based PG device achieved ultra-high gravimetric short-circuit current and power density that are both the highest compared to reported environmental energy harvesting technologies (FIGS. 17A-17B, Tables 2, 3)

[0098] It is practically important that the output of the d evices can be further scaled up simply through series and parallel connections of multiple devices. As shown in Figures 4D-4E, enabled by the convenient preparation and superior flexibility, an integrated wearable device with higher output voltage can be facilely obtained by connecting single PG devices in series, with repeating units of potential that add up to 11.4V (FIGS. 18A-18C). A prototype of an energy-harvesting device was also demonstrated by connecting 20 PG units in series (FIG.

[0099] 4F). The voltage of the prototype device is high enough to directly power an LED flashlight (FIG. 4G). In addition, a prototype composed of 50 PG units can charge a cell phone through Attorney Docket No. 10046-658W01

[0100] the connection of a voltage converter, exhibiting outstanding power generation performance (FIG. 4H).

[0101] Thus, in another aspect, disclosed is an electrochemical cell comprising the energyharvester according to any preceding claim in electrical communication with a first electrode, a second entangled polymer network in electrical communication with a second electrode, a separator disposed between the first and second energy harvesters. The cell can further comprise an electrolyte. The second entangled polymer network can comprise the same polymers as the energy harvester, wherein said same polymers are not or less non-homogenously distributed, are not or less phase separated, or does not have or have less first and second portions. The energy harvester can have a lower electrical potential relative to the second entangled polymer network. In the disclosed cells, the x-ray diffraction pattern of the second entangled polymer network does not include a peak at about 0.38 °20.

[0102] Further disclosed are batteries comprising one or more of the electrochemical cells disclosed herein. Also disclosed are articles, such as sheets, cloth, clothing, etc. that comprise one or more of the disclosed energy harvesters or electrochemical cells thereon.

[0103] EXAMPLES

[0104] The following examples are set forth below to illustrate the methods and results according to the disclosed subject matter. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative methods, compositions, and results. These examples are not intended to exclude equivalents and variations of the present invention, which are apparent to one skilled in the art.

[0105] Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric. There are numerous variations and combinations of reaction conditions, e.g., component concentrations, temperatures, pressures, and other reaction ranges and conditions that can be used to optimize the product purity and yield obtained from the described process. Only reasonable and routine experimentation will be required to optimize such process conditions.

[0106] PEDOT: PSS aqueous solution (1.1-1.3% solid content, CleviosTM PHI 000) was purchased from Heraeus. Dimethylformamide (DMF), NaCl were purchased from Sigma-Aldrich. Polyester wipe (TX1112, Texwipe) was purchased from Amazon. Attorney Docket No. 10046-658W01

[0107] Example 1: Fabrication of gel in PSLO

[0108] Gel in PSLO was fabricated by directly drying the PEDOT: PSS and DMF mixed solution. Firstly, DMF was added into PEDOT: PSS aqueous solution to form a mixed solution with 5 vol% DMF. The well-mixed solution was sonicated by an ultrasonic processor (VCX500, SONICS) for one minute. The mixture was dropped cast on glass or fabric before drying at 60°C for 17 hours to obtain dry gel or gel / fabric sample in PSLO, respectively. Example 2: Fabrication of gels in PSL1-5

[0109] In a typical synthesis, PEDOT: PSS aqueous solution was mixed with DMF with a volume ratio of 1:1. The well-mixed solution was sonicated by an ultrasonic processor for one minute. Then, the obtained mixture was heated at 90°C in an oven for 17 hours. The as-prepared hydrogel was washed with deionized (DI) water to remove both DMF and ungelated residues to obtain the PSL1. PSLl / fabric samples were fabricated by firstly dip-coating the PEDOT: PSS / DMF solution on fabric and then immersing it into DMF, followed by heating at 90°C in an oven for 17 hours. The PSLl / fabric sample was obtained after being washed with DI water. Gel-PS2 to PSL5 were obtained by multiple H-D cycles on PSL1. In each H-D cycle, the gel was first soaked in water or NaCl solution (up to 0.6 mol L-1) for 10 minutes and was then dehydrated by air or heat (< 90°C).

[0110] Example 3: Characterizations

[0111] Atomic force microscopy (AFM) phase images were acquired by the Park NX10 system in tapping mode. Transmission wide-angle X-ray scattering (WAXS) measurements were performed by SAXSLAB’s Ganesha instrument, with a microfocus Cu k-alpha source operated at 50kV and 0.6mA. X-ray photoelectron spectroscopy (XPS) spectra were collected by Kratos X-ray Photoelectron Spectrometer. The source is Al 1486.6 eV monochromatic, the magnification is 1×103, and the resolution is 80 nm. The FTIR spectra were conducted by the FTIR spectrometer (Infinity Gold FTIR, ThermoMattson) equipped with liquid nitrogen-cool ed narrow-band mercury cadmium telluride detector using an attenuated total reflection cell equipped with Ge crystal.

[0112] Example 4: Electrical measurement

[0113] Open circuit voltage (Voc) and cyclic voltammetry (CV) curves of PEDOT: PSS gel samples at different phase separation levels were collected on a BioLogic VMP3 Potentiostat via a three-electrode system with platinum foil and Ag / AgCl as counter electrode and reference electrode, respectively. Voltage-time curves of PG devices were tested by a two-electrode system on the same equipment. The short circuit current (SSC) and output current curves were collected on Keysight B1500A Semiconductor Device Parameter Analyzer. Attorney Docket No. 10046-658W01

[0114] Example 5: Calculations of Donnan potential

[0115] The starting point for the analysis of Donnan potential is the electroneutrality of the system at equilibrium. According to the condition of an electrochemical equilibrium, the electrochemical potentials of mobile ion "i" are equal in gel and bulk electrolyte:

[0116]

[0117] here, the superscripts s and g indicate the electrolyte solution and hydrogel, respectively, R, T, F are the gas constant, the absolute temperature, and the Faraday constant, respectively. ju.0'-’, and μ0,gare the standard chemical potential of ion "i" in electrolyte and hydrogel and are the same in conventional assumption (Safronov, A. P. et al. in Water and the Cell 273- 284 (Springer, 2006)). z.i and a are the valency and activity of the mobile ion i, respectively, and F are the Galvani electric potential of the hydrogel and electrolyte. Since

[0118]

[0119] is the Galvani electric potential difference between hydrogel and electrolyte, it can be easily solved from Equation (2) (Guo, H. et al. Quantitative observation of electric potential distribution of brittle polyelectrolyte hydrogels using microelectrode technique. Macromolecules 49, 3100-

[0120]

[0121] For an ideal system, the activity a of mobile ion can be approximate with concentration c, and Equation (3) becomes:

[0122]

[0123] Equation (4) can be applied to both mobile cation and anion that exist simultaneously in solution and hydrogel at equilibrium. In this work, all the electrolyte salts are metal chlorides. Thus, Equation (4) gives:

[0124]

[0125] here, Zm is the valency of the mobile cation m (m = K, Na, Mg, Ca, Al) and za is the valency of Cl" and equals -1, csmand

[0126]

[0127] are the concentration of mobile cation m and anion CF in electrolyte, cgmand cgaare the concentration of mobile cation m and anion Cl- in hydrogel, respectively. By solving Equation (5), one obtains:

[0128]

[0129] At equilibrium, the amount of the residual ions in the electrolyte is far higher than the diffused ions into the gel, thus the changes in the ion concentration in the electrolyte can be neglected after contact with gel: Attorney Docket No. 10046-658W01

[0130]

[0131] where co is the salt concentration of the bulk electrolyte. Besides, in order to meet the electroneutrality, the positive charges carried by injected mobile cations in the PSS phase must be equal to the negative charges that comprise fixed negative charges and injected

[0132]

[0133] where zS03is the valency of the fixed charge group in PSS and equals -1, cgis the fixed charge density of PSS phase. Substituting Equation (7-8) into Equation (6) gives:

[0134]

[0135] The screening effects of the fixed negative charges in the PSS phase will lead to c » cgCl, and then the left part of Equation (9) becomes:

[0136]

[0137] From Equation (9-10), one obtains:

[0138]

[0139] By substituting Equation (7, 11) into Equation (4), <bDcan be expressed as:

[0140]

[0141] Equation (12) suggests <bDis determined by electrolyte concentration, the valency of the mobile cation, and the fixed charge density of the PSS phase.

[0142] The potential difference (A^) between gels in PSLO and PSL5 can be calculated from the difference between their < / > D according to Equation (12):

[0143]

[0144] Equation (13) infers that the open-circuit voltage is determined only by the c / difference between the gel electrodes and will not be affected by the electrolyte concentration. A two- dimensional geometry was adopted via COMSOL Multiphysics 4.4 in consideration of the PG device based on the analysis above.

[0145] Example 6: Resistance of different electrolyte concentrations

[0146] Consider an electrolyte solution at a molar concentration c, where each formula unit give rise to v+ cations and v anions. The molar concentration of each type of ion is therefore vc (with v = v+ or vj, and the number density of each type is VCNA. The flux of ion is therefore Attorney Docket No. 10046-658W01

[0147] Jion= δvcNA(SI) where 5 is speed drift of the ion, NA is the Avogadro constant. Each ion carries a charge ze, so the flux of charge is

[0148] Jcharge= zδvcNAe = zδvcF (S2) where F is Faradic constant. Since = uE, where w is mobility of ion, and E is electric field, the flux is

[0149] Jcharge= zuvcFE (S3) The current, I, through the window due to the ions considered is the charge flux times the area A

[0150] I = JchargeA = zuvcFEA (S4) Because the electric field is the potential gradient, A<p / l, where I is the length of the window, one can write,

[0151]

[0152] Current and potential difference are related by Ohm’s law, ΔΦ = IR, so it follows that

[0153]

[0154] Example 7: Energy analysis

[0155] According to the phase separation-induced power generation mechanism, the power generation process of the PEDOT: PSS gel can be divided into two steps. The first step (charging process) is the energy harvesting and storage step, in which the “environmental energy” was harvested and stored in the gel. In the following power output step (discharging process), the stored energy was released to power the external device.

[0156] In the charging process of gel in PSL1, the environmental energy harvesting is realized by enhanced phase separation in PEDOT: PSS, which is induced by H-D cycles. Since the hydration process is spontaneous and doesn’t require any external energy input, the total energy input (Einput) of the charging process can be quantified as only the energyconsumption for the dehydration during the charging process. Therefore, the energy efficiency (q) is estimated based on: Attorney Docket No. 10046-658W01

[0157]

[0158] where Eoutput is the experimentally measured output energy density, I and V are the output current density and voltage, respectively. / JPEDOT: PSS is the energy for water evaporation in PEDOT: PSS hydrogel (1700 J g-1, measured by differential scanning calorimetry (DSC)), m is the mass of evaporated water during a single charging process, calculated by the following equation:

[0159]

[0160] where M is the mass loading of the gel (0.8 mg cm-2) on fabric, Aq is the change in water content of the PEDOT: PSS hydrogel during a single charging process, n is the charging time. A minimum Aq of 8% is required to accomplish the charging process, and m is ~0.07 mg cm-2. When the charging time is 8, an E'input of ca. 0.94 J cm-2can be calculated from the relations above, and Eoutput is ~ 0.0067 J cm-2based on experiment results. Finally, q is estimated to be ~1%, which is comparable with other environmental energy-based power generators.

[0161] Example 8: Swelling behavior of PEDOT: PSS gels

[0162] PEDOT: PSS gels undergo phase separation into a two-phase structure, in which the associations of ir-conjugated PEDOT-rich crystalline domains construct a rigid framework and the soft PSS-rich domains interconnected with PEDOT-rich domains to form an integrated structure. When in contact with the electrolyte, only the hydrophilic PSS phase will swell while maintaining the interconnected networks of the rigid PEDOT framework. Therefore, the swelling ratio of the PSS phase is governed by the physical confinement of the rigid PEDOT framework, which is related to the phase separation level (Feig, V. R. et al. Mechanically tunable conductive interpenetrating network hydrogels that mimic the elastic moduli of biological tissue. Nat. Commun. 9, 2740, (2018).). Thus, the decrease in swollen water content confirms the increasing phase separation level from PSL1 to PSL5.

[0163] Example 9: Microstructure and electric potential of PSL0

[0164] AFM, WAXS test was conducted to investigate the structure of PSL0. As shown in Figure 6A, the PEDOT-rich domains (bright regions) are largely distributed, suggesting that PEDOT was well-blended with PSS (dark region) and related to a low degree of phase separation. In Figure 6B, WAXS results show that the intensity of (020) peak of PSL0 is much lower than that of PSL1, demonstrating a low degree of ordering in PEDOT’ s tt-tt Attorney Docket No. 10046-658W01

[0165] stacking. The average electric potential of PSLO in 0.6mol / L NaCl solution is 0.525 V (FIG.

[0166] 2C). Combining the results of morphological observation and crystallinity, it is further confirmed that PSLO has the lowest phase separation level based on the relation between the phase separation and electric potential.

[0167] To understand why PSLO exhibited a lower phase separation level despite its similar morphology to PSL1, XPS characterization was performed to investigate the changes in composition content in different PEDOT: PSS assemblies. It is clearly seen in Figure 6D that PSL1 and PSL5 have less content of PSS (-168 - 169 eV) than PH1000 and PSLO do, suggesting that PSS was removed during the high-temperature gelation process, stemming from the increased phase separation (Wang, Y. et al. A highly stretchable, transparent, and conductive polymer. Sci. Adv. 3, el602076, (2017); Xu, B. et al. Functional solid additive modified PEDO'DPSS as an anode buffer layer for enhanced photovoltaic performance and stability in polymer solar cells. Sci. Rep. 7, 45079, (2017)).

[0168] Example 10: Composition of PEDOT: PSS gels

[0169] FTIR characterization was used to reveal the chemical composition of PH1000, PEDOT: PSS gel in PSLO, PSL1, and PSL5 (FIG. 7). All samples show the same peak at 1637 cm-1, which corresponds to C=C stretching vibration of both PEDOT and PSS (Xiong, S. et al. Conductivities enhancement of poly(3,4-ethylenedioxythiophene) / poly(styrene sulfonate) transparent electrodes with diol additives. Polym. Bull. 70, 237-247, (2013)). The peaks related to sulfonate group -SO3 (1195 cm-1) and C-S bond (973 cm-1, 682 cm-1) from PSS are also found in all the curves (Xiao, P. et al. Integration of Graphene, Nano Sulfur, and Conducting Polymer into Compact, Flexible Lithium-Sulfur Battery Cathodes with Ultrahigh Volumetric Capacity and Superior Cycling Stability for Foldable Devices. Adv. Mater. 29, 1703324, (2017)). Besides, no characteristic peaks of DMF (C-N stretching at 866 cm-1, O=C-N stretching at 659 cm-1) can be found in the gel in PSLO, PSL1, and PSL5, indicating the full removal of DMF in PEDOT:PSS hydrogels (Jacob, M. M. et al. FTIR studies of DMF plasticized polyvinyledene fluoride based polymer electrolytes. Electrochim. Acta 45, 1701-1706, (2000)). These results reveal that no chemical composition change occurs during the gelation process of PEDOT:PSS hydrogel.

[0170] Example 11: Preparation of PEDOT: PSS gels with different phase separation levels Two different gelation strategies were adopted together with multiple H-D cycles to increase the phase separation level of PEDOT:PSS gel. By using different gelation methods, gels in PSLO and PSL1 were synthesized respectively. Then the PSL2-5 can be obtained from PSL1 by multiple H-D cycles. The electric potential of PEDOT:PSS gels can serve as the Attorney Docket No. 10046-658W01

[0171] indicator of the phase separation level by relating the evidence from characterizations such as AFM, WAXS, and the measured potential values (FIGS. 6A-6D). The details of the processing of the obtained PEDOT: PSS samples with six phase states is summarized.

[0172] The gel in PSLO with a low degree of phase separation between PEDOT and PSS was simply prepared by directly drying the PEDOT: PSS solution with 5 vol% DMF at low temperature (see Methods for details). The formation of PEDOT:PSS gel can be explained as follows. Firstly, due to the higher affinity with DMF than w'ater, the PEDOT chains will suffer a conformational change from a random coil to an expanded -coil structure, along with the rearrangement of PEDOT chains to form rigid PEDOT-rich domains through K-TI interaction. Then, the hydrophobic PEDOT-rich domains that connect w'ith PSS chains at the outer layer can work physical crosslinking points and induce the physical crosslinks of PSS chains to form the 3D network of the gel.

[0173] For the preparation of gel in PSL1, a high-temperature gelation method was applied. During the process, PEDOT: PSS solution was mixed with a higher concentration of DMF (50 vol%), and then was heated at an elevated temperature (90°C) (Yao, B. et al. Ultrahigh-Conductivity Polymer Hydrogels with Arbitrary Structures. Adv. Mater. 29, 1700974, (2017); Feig, V. R. et al. An Electrochemical Gelation Method for Patterning Conductive PEDOT: PSS Hydrogels. Adv. Mater. 31, 1902869, (2019)). When introduced with an elevated temperature and a higher content of DMF, as the movement of PEDOT and PSS chains becomes more active, the separation between PEDOT and PSS would be enhanced and lead to an improved crystallinity of PEDOT over a long duration of gelation to obtain PSL1. Then, PSL1 can be further tuned toward higher PSLs (i.e., PSL2 to PSL5) simply by multiple H-D cycles. During hydration, PSS was solvated by water, and hydrogen bonds between PSS and water could thus be formed, while PEDOT could not be solvated (as physical crosslinking points). As the hydrogen- bonded water evaporated in the subsequent dehydration process, the hydrogen-bonding interaction occurred between sulfonate groups, leading to increased interchain interaction between PSS chains (Zhou, J. et al. The temperature-dependent microstructure of PEDOT / PSS films: insights from morphological, mechanical and electrical analyses. J. Mater. Chem. C 2, 9903-9910, (2014)). Each H-D concentrated the PEDOT: PSS and resulted in more interconnected PEDOT-rich / PSS-rich domains, and finally gave the product with high phase separation level. By using these strategies, PEDOT: PSS gels with five phase separation levels were generated, with the details of processing summarized in Table 1. Attorney Docket No. 10046-658W01

[0174] Table 1. Summary of PEDOT: PSS gels with different phase separation levels and the corresponded potential.

[0175] Phase separation level Electric potential (V vs. Ag / AgCl) Number of H-D cycle

[0176] PSL1 0.334 ± 0.022 1-2

[0177] PSL2 0.302 ± 0.022 2-4

[0178] PSL3 0.270 ± 0.022 4-6

[0179] PSL4 0.238 ± 0.022 6-8

[0180] PSL5 0.200 ± 0.022 8-10

[0181] Example 12: Electricity generation performance of PEDOT: PSS-based PG device The phase separation level of PEDOT: PSS gel can be enhanced via multiple H-D cycles. As shown in Figure 8A, Voc between PSLO and PEDOT: PSS gel gradually increased from 0.20 V to 0.34 V as the phase separation level of PEDOT: PSS gel increased from PSL1 to PSL5. As a result, Q (i.e., charge delivered during discharge) gradually increased as environmental energy accumulated in the gel, reaching the highest value of 14.26 C g'1(FIG.

[0182] 8B). Correspondingly, power output between PSL0 and PEDOT: PSS gel also increased as the phase separation level increased, reaching up to 12.7 W g-1.

[0183] CV experiments of PSLO and PSL5 were conducted at different scan rates (FIGS. 9A- 9C). For the measurement of double-layer capacitance (Cai), the difference in current, / , between anodic current (ia) and cathodic current (ic) at V = 0.25 V was calculated from the C V curves at different scan rates (5, 10, 15, 20, 25 and 30 mV s-1), which can be given below:

[0184] j = G - (S9) The relation between;, the scan rate v, and the Cdi is:

[0185]

[0186] Therefore, the slope of j / 2 as a function of v gives a straight line with the slope equal to Cdi. The obtained Cdi for PSL0, PSL5 are 29.3 mF g-1and 42.7 mF g-1, respectively.

[0187] Example 13: Multiple charge / discharge experiments

[0188] Multiple charge / discharge experiments were conducted to further study the mechanism and stability of the phase-separation induced voltage. As shown in Figure 10A, Attorney Docket No. 10046-658W01

[0189] after discharging, the EAg / AgClof the discharged PEDOT: PSS gel (d-PSL5) is at the same as PSL1. During five charge / discharge cycles, PSL5 shows good reversibility and good cycling stability. In order to further verify the dependence of the electrical potential on the phase separation, the phase separation state of the discharged-PSL5 (d-PSL5) gel were characterized. Even though d-PSL5’s electrical potential is close to PSL1, WAXS and AFM results show that d-PSL5 has a phase separation state similar to PSL3 rather than PSL1. The WAXS in Figure 10B shows that compared to PSL-1 and PSL-5, (010) peak of d-PSL5 has an intensity similar to that of PSL3. The same phenomenon is also revealed by AFM phase images. Unlike sparsely distributed PEDOT domains in PSL-1 (FIG. 10D) and the aggregated structure of PSL5 (FIG. 10F), d-PSL5 shows a less phase-separated morphology (FIG. 10C) which is comparable to PSL3 (FIG. 10E). During the discharging process between gels in PSL5 and PSLO, positive charges (i.e., holes) transport from PSLO to PSL5 through the external circuit as current flow due to the higher potential of PSLO. The injection of holes into the PEDOT phases would increase the repulsion among the PEDOT crystals due to the electrostatic interaction, inducing the dissociation of the aggregated structure. Another result from the superfluous positive charges is that the electric potential of d-PSL5 is higher than that of the gels with the same phase separation level (i.e. PSL3). In summary, the cause for the mismatch between electric potential and phase separation state in d-PSL5 is the excess holes injected from PSLO through the external circuit.

[0190] To verify this assumption, regeneration experiments of d-PSL5 were conducted under different conditions. The d-PSL5 was first generated by multiple H-D cycles without any other treatment, which means the excess holes would be retained in the gel during the whole process. Figure 10G shows that the electric potential of d-PSL5 can be only recovered to PSL3 under this condition. By contrast, if the holes are free to move outside the gel and reach charge balance during the regeneration process via ground connection in the electrolyte solution (0.6 mol L1NaCl), the E'Ag / Agci of d-PSL5 would drop from PSL1 to PSL3, even without any process requiring environmental energy input such as H-D treatment (FIG. 10H). Eventually, the d-PSL5 can be successfully regenerated to PSL5 after the following H-D cycles (FIG. 101). These results show that the excess holes are responsible for the positively shifted electric potential in d-PSL5 in ungrounded case. Upon ground connection, the excess holes are free to move outside the gel and the dependence between phase separation level and electric potential will recover.

[0191] As shown in Figure 11A, the EAg / AgClof the PSL0 is the same as PSL1 after discharging and can be recovered to PSLO via ground connection in electrolyte solution (0.6 Attorney Docket No. 10046-658W01

[0192] mol L-1NaCl). The good reversibility during five charge / discharge cycles reveals its good cycling stability. As mentioned in Figures 10A-10I, the ground connection is able to reach charge balance in PEDOT: PSS gel. In the case of PSLO, after being grounded in DI water overnight, the resulting d-PSLO is able to be recovered to the low phase separation level with the same EAg / AgClof the PSL0. WAXS and AFM results show that d-PSLO has a phase separation state similar to PSLO. The WAXS in Figure 11 B shows that the intensity of (010) peak from d-PSLO is close to that of PSLO. Compared to the AFM phase images of PSLO (FIG. 11D), the phase separation state shown in d-PSLO (FIG. 11C) does not show any obvious change. Having ruled out the effects of excessive holes via ground connection, the dependence between phase separation level and electric potential is recovered.

[0193] Example 14: Demonstration of PG devices

[0194] A portable PG device (5x3 cm2in dimensions) with good flexibility and high robustness is also demonstrated (FIG. 12A). As shown in Figures 12B-12C, enabled by the convenient preparation and superior flexibility, an integrated wearable device that is able to withstand bending without mechanical failure can be facilely obtained. Benefiting from the simple solution-based preparation method, the gel loaded on fabric with large sizes up to about 80x50 cm2can be easily produced (FIG. 12D).

[0195] Example 15: Short-circuit current

[0196] Analysis of short-circuit current further demonstrated that a record-high peak current density of 18.09 A g-1can be achieved (FIG. 13).

[0197] Example 16: Power output

[0198] The power generation performance of the PG device composed of gels in PSLO and PSL5 was investigated by measuring output voltage and current. The output performance of the PG device was investigated with different external loadings in 0.6 mol L NaCl. As shown in Figure 14, as the loading resistance increases, the output voltage increases, accompanied by the decrease in output current. When the loading resistance is 100, a balanced high output voltage, and current can be achieved, resulting in the highest output power density of 1.27 W g-1, which is obtained by multiplying output voltage and output current, further showing the excellent power generation performance of the PEDOT: PSS gels.

[0199] The maximum power output for PG in NaCl electrolyte was tested with concentrations ranging from 0.00006 mol L-1to 6 mol L-1(FIGS. 15A-15B). As can be seen from Figure 15A, the output voltage did not show obvious change ranging from 0.00006 mol / L to 6 mol / L when the external loading the optimized to produce the highest power in each concentration, while the output current gradually increased as electrolyte concentration increased. As Attorney Docket No. 10046-658W01

[0200] concentrated NaCl solution is more conductive than the diluted counterpart, it reduces the resistance of the PG device, minimizing the internal resistive loss during operation. As a result, the power output is positively correlated to the concentration of NaCl electrolyte (FIG. 15B), exhibiting the variation of output current and power when charging or powering electrical devices with different resistances.

[0201] Example 17: Cycling stability

[0202] After discharge, the PG device can be successfully recharged without obvious decay in neither peak current density nor Q within 5 cycles (FIGS. 16A-16B), showing good cycling stability. The regeneration process of the PSLO side is to immerse the PSLO in DI water overnight with grounding. And the regeneration method of the PSL5 side is multiple H-D cycles with grounding.

[0203] Example 18: Comparison of power generation performance with previous literature The power generation performance of the present invention is compared with some state-of-the-art representative works with different environmental energy harvesting mechanisms in terms of voltage, power, and current. An exemplary aspect of the invention is first compared the open-circuit voltage, areal short circuit current density, and areal power current density of an exemplary aspect of the invention to the counterpart values in other works, since these values are listed in most literature. As summarized in Table 3, an exemplary aspect of the invention has a comparably high current density (4287 μA cm-2) and Voc (0.34V) compared with other works, showing the potential for practical use with the balanced high performance.

[0204] Gravimetric power density and current density of an exemplary aspect of the invention is also compared with other works. Both values are based on the mass of active materials. Specifically, for the works based on capacitance change, moist-electric, and evaporating potential, the active materials were defined as the materials that interact with water or moisture to generate electricity. As for the thermoelectric devices, the active materials are the functional component in the power generator, such as those inorganic or organic semiconductors. In cells based on thermogalvanic effect, the redox couples in the electrolytes are considered as active materials. For those works that didn’t directly provide the mass-normalized power (current) density, the gravimetric densities were estimated by using the output power divided by the mass of active materials. As shown in Figures 17A-17B and Table 2, the exemplary aspect of the invention outperforms the other ones with the highest gravimetric power density (1.27 W g-1) and the highest gravimetric current density (18.1 A g-1), clearly demonstrating the impressive performance of PEDOT: PSS gel in power generation.

[0205] T Attorney Docket No. 10046-658W01

[0206] A difference in the invention from other studies is the working mode: the environmental energy can be gradually accumulated and stored in PEDOT: PSS gels. Other works rely on simultaneous stimuli such as kinetic force (e.g., drops’ impinging, waving), evaporation, moisture gradient, and temperature gradient, limiting the working environments. Even if the required external stimuli are present, the varying conditions such as humidity, rate of droplet’s impinging, speed of water flow, and temperature gradient affects the power output, yielding unsatisfactory performance at unoptimized conditions. In contrast, power generation via PEDOT: PSS gels only require liquid as an electrolyte, thus possessing larger application scenarios. Many devices composed of hard plates based on mechanisms such as triboelectric, and thermogal vanic effects are not bendable and thus can hardly be wearable or portable devices, which will become heavy and bulky when scaling up. On the contrary, PEDOT: PSS-based PG device can be made into both large and small devices for its flexibility and scalability (FIGS. 12A-12D). In conclusion, PEDOT: PSS PG device is promising for power generation with high performance and broad application scenarios.

[0207] Table 2. Summary on open circuit voltage and areal short circuit current density of representative power generation works.

[0208] O „pen S.hort „ Power working Energy A. ct.i.ve ci.rcui.t. circuit, d,ensity „ mec,hanism source materia ils voltage, cur..ren.t. (,u Note (V) density A (uA

[0209] cm cm *)

[0210] Phase separation- Environmental PEDOTtPSS „ „,,

[0211] 0 54 4 o7 - 53 / induced potential energy hydrogel

[0212] Carbon nanotube,,c,

[0213] 0.5b / / / yarn

[0214] Capacitance Water-based

[0215] change kinetic energy

[0216] Multi-walled „,,., „„,,., 0.65 8.89 / / carbon nanotube

[0217] ...,, Polvdiallyl „,,,,,,,.,.,. Environmental ' • 0.08 (with „ RH = Moist-electric dimethyl 0.95,. 0.076 „„„

[0218] energy. loadings) 25%

[0219] ammonium ° Attorney Docket No. 10046-658W01

[0220] chloride (PDDA)

[0221] and polystyrene

[0222] sulfonic acid

[0223]

[0224] Sodium alginate

[0225] (SA), silicon

[0226] dioxide

[0227] nanofiber,,rRH =

[0228] , 0.5 / 1200

[0229] (SiO2), and 100% reduced

[0230] graphene oxide

[0231]

[0232] Carbon black T 0.06 0.0212

[0233] film

[0234] „. Geobacter

[0235] "vapora irij, sulfurreducens 0.53 / 685

[0236] p

[0237] rotential,.

[0238] biofilm

[0239] Living leaf 0.25 / 0.1 /

[0240] PTFE film 143.5 100* 5010 /

[0241] Triboelectric effect Liquid

[0242]

[0243] sugar

[0244] Water-based

[0245] kinetic energy

[0246] Drawing potential c ' / c ^ICIIC0.03 / 0.0192 /

[0247] S1 / S1O2 waler

[0248] Waving potential

[0249]

[0250] ^.1 0.55* / /

[0251] PE 1 substrate

[0252] , AT = ThermoelectricL-ov"”r, e0.019 (4. 30 °C thermal Ai^Se film.. / 230n„ effect - units; (27 C ~ energy57oC) Attorney Docket No. 10046-658W01

[0253] PEDOT-doped AT = and olemaine- 40 °C 0.03

[0254]

[0255] doped carbon (20 °C ~ nanotube 60 °C) 1 -! - 1 - 1 - 1 - 1 AT = FeCh / FeCh- 72o., based redox 0.39 4670 334 ".t(25 °C ~ electrolytenn o,- ) Thermogalvanic

[0256] effect Fe(CN)637Fe AT =

[0257] (CN)S4-n50 °C. / ,t0.186 41600 1770o„ electrolytes with (20 C ~ GdmCl 70 °C)

[0258] Gelatin with

[0259] Fe(CN)637Fe

[0260] Thermogalvanic (CN)S4AT = and (thermogalvanic 8.5 °C

[0261]

[0262] 3.56 thermodiffusion effect) and KC1, (20 °C ~ effect NaCl, KN0370 °C) (thermodiffusion

[0263] effect)

[0264] Thennodiffu sion Cellulosic AT =

[0265] 0.118

[0266]

[0267] effect membrane 5.5 °C *values are calculated based on the reported short circuit currents and corresponding area.

[0268] Table 3. Summary on gravimetric short circuit current and gravimetric power density of representative power generation works with different mechanisms.

[0269] Short

[0270] Power

[0271] Mechanism Active materials circuit

[0272] curren density Notes

[0273] t (W g'1) Attorney Docket No. 10046-658W01

[0274] density

[0275] (A g’*)

[0276] F. T. T..

[0277] Phase separation-T,,

[0278] .. / ., PEDO1: PSS hvdrogel1

[0279] 1o8.n

[0280] 0n.

[0281] 9 1.27

[0282]

[0283] induced potential

[0284] F. T. T..

[0285] Capacitance Carbon nanotube yarn 0.35 0.25 /

[0286] change-indu ed Multi-walled carbon „

[0287]

[0288] P°Eentialnanotube °'69°'0395

[0289] LT „

[0290] Protein nanowire 0.015 * 0.0216 *

[0291] 50%

[0292]

[0293] Graphene oxide film 0.03 * 0.0214 *

[0294]

[0295] i PPy foam 0.1 * 0.0069 * CC"

[0296] Moist-electric 85%

[0297] ' 0.0037 ' 4.25X10'4' RH =

[0298] PS 8 membrane

[0299] 5e

[0300] * * 30%

[0301] i ■ ■ i i Polydiallyl dimethyl 3x10"

[0302] ammonium chloride "...T,TT

[0303] (PDDA) and,,. 2.2x10

[0304] ,.... loading6

[0305] 25% polystyrene sulfonic

[0306] acid (PSS)

[0307]

[0308]

[0309] Thermogalvanic /

[0310] ,., • FeCh / FeCE-basedn„n n„ 63 C thermoelectric,,.,. 0.42 0.0299o„

[0311] rc. redox electrolyte (25 C ~

[0312] effect (TG / TE)Jc™

[0313] 90 C) Attorney Docket No. 10046-658W01

[0314] Fe

[0315] (CN)637Fe

[0316] (CN)e4_redox pair as AT =

[0317] active material for 40 °C

[0318] 0.07 * 0.001

[0319] positive electrode (20 °C ~

[0320] and a solid Prussian 60 °C)

[0321] blue nanoparticle

[0322] negative electrode

[0323] AT =

[0324] c

[0325] (CN)637Fe 1.25 0.0355 *

[0326] (CNF4' electrolyte ’150 O(. ~

[0327] H U 1

[0328] Fe AT =

[0329] (rCiMN)SeNe!l6e3c / throeflytes 0.092 0.00393 (2500o°(;. ~

[0330] with GdmCl 70 °C)

[0331] .... 1

[0332] AT =

[0333] A, „ 5.04 9.58X10-530 °C

[0334] g> Se f1|mx I0.,,,(27.c_

[0335]

[0336] PAAm hydrogel with. T =

[0337] Fe ~ 1.62 x 9.5 x 10 20 °C

[0338] (CN)63- and Fe IO'4*7* (25 °C ~

[0339] (CN)6445 °C)

[0340] *values are calculated based on the reported short circuit currents (or powers) and corresponding mass.

[0341] Example 19: Demonstration of portable PG devices

[0342] The assembled PG devices can be scaled up to 50 devices as shown in Figure 18A. 'The easy-to-unfold feature of the flexible PG devices makes it suit for practical use, since the H-D -based charging process will be facilitated by exposing a larger area to ambient air (FIGS.

[0343] 18B-18C). The portable PG devices can power a flashlight (FIG. 4G) by 20 units and charge a cell phone (FIG. 4H) by 50 units through a DC converter, demonstrating its potential practicality.

[0344] Although several embodiments of the invention have been disclosed in the foregoing specification, it is understood by those skilled in the art that many modifications and other embodiments of the invention will come to mind to which the invention pertains, having the Attorney Docket No. 10046-658W01

[0345] benefit of the teaching presented in the foregoing description and associated drawings. It is thus understood that the invention is not limited to the specific embodiments disclosed hereinabove and that many modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although specific terms are employed herein, as well as in the claims which follow, they are used only in a generic and descriptive sense and not for the purposes of limiting the described invention nor the claims which follow

Claims

Attorney Docket No. 10046-658W01CLAIMSWhat is claimed is:

1. A method of harvesting environmental energy, comprising subjecting an energy harvester to one or more hydration / dehydration cycles, wherein the energy harvester comprises a first polymer system comprising a conductive polymer and a second polymer system comprising a polyanionic polymer.

2. The method of claim 1, wherein the conductive polymer comprises apoly (thiophene), poly(aniline), poly(pyrrole), poly(carbazole), poly (azepine), or polyphenylene sulfide.

3. The method of any one of the preceding claims, wherein the conductive polymer comprises a poly (thiophene), or a combination thereof, preferably poly(3,4-propylenedioxythiophene) or poly(3,4-ethylenedioxythiophene).

4. The method according to any preceding claim, wherein the conductive polymer has the formula:wherein X is S, O, or NR, wherein R is H or Ci-4alkyl. R1and R2are independently choses from H, Ci-6alkyl, Ci-6alkoxy, Ci-6haloalkyl, Ci-6haloalkoxy, F, Cl, Br, I, CN, NO2, and wherein R1and R2, together with the two carbons to which they are attached, may form a five, six, or seven member ring.

5. The method of claim 4, wherein X is S, and R1and R2together form a six or seven member ring, wherein said ring optionally has two oxygen atoms.

6. The method of any one of the preceding claims, wherein the polyanionic polymer comprises a poly-carboxylic acid, a poly-sulfonic acid, a poly-phosphonic acid, or a combination thereof.

7. The method of any one of the preceding claims, wherein the polyanionic polymer comprises a poly(acrylic acid), poly (methacrylic acid), poly(2-acrylamido-2-methyl-l-Attorney Docket No. 10046-658W01propanesulfonic acid), polystyrene sulfonic acid, polyvinyl sulfonic acid, polyvinylphosphonic acid, or a combination thereof.

8. The method of any one of the preceding claims, wherein the conductive polymer and the polyanionic polymer are present in a wt.% ratio from 5:1 to 1:5, 5:1 to 1:1, from 5:1 to 2.5:1 from 4:1 to 2:1, from 2.5:1 to 1:2.5, from 2.5:1 to 1:1, from 1.5:1 to 1:1.5, from 1.5:1 to 1:1, from 1:1 to 1:1.5, from 1:1 to 1:2.5, from 1:2 to 1:4, from 1:2.5 to 1:5, or from 1:1 to 1:5, preferably from 1:2 to 1:4, or 1:2.5.

9. The method of any one of the preceding claims, wherein the hydration / dehydration cycle comprises contacting the harvester with an aqueous solution for a first period of time to form a hydrated harvester, and then exposing the hydrated harvester to dehydrative conditions for a second period of time to form a dehydrated harvester.

10. The method of any one of the preceding claims, wherein the first period of time is from 0.1-100 minutes, from 0.1-50 minutes, from 0.1-25 minutes, from 0.1-10 minutes, from 0.1-5 minutes, from 0.1-2 minutes, or from 0.1-1 minute.

11. The method of any one of the preceding claims, wherein the aqueous solution comprises dissolved salts, preferably at a concentration from 0.1-4 M, from 0.1-3 M, from 0.1-2 M, from 0.5-2M, from 0.5-1.5 M, from 0.1-1 M, from 0.25-1M, from 0.5-1M, or from 1-2M.

12. The method of any one of the preceding claims, wherein the aqueous solution comprises river water (including stream, creek, etc), rainwater, lake water, non-potable water, wastewater, ocean water, or a combination thereof.

13. The method of any one of the preceding claims, wherein the dehydration conditions comprise air drying, exposure to sunlight, exposure to thermal energy, or a combination thereof.

14. The method of any one of the preceding claims, wherein the dehydrative conditions reduce the water content in the hydrated energy harvester by at least 40 wt.%, at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 85 wt.%, at least 90 wt.%, or at least 95 wt.%.Attorney Docket No. 10046-658W0115. The method of any one of the preceding claims, comprising subjecting the energy harvester to at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 hydration / dehydration cycles.

16. The method of any one of the preceding claims, comprising subjecting the energyharvester to 2, 3, 4, 5, 6, 7, 8, 9, or 10 hydration / dehydration cycles.

17. An energy harvester, comprising an entangled polymer network comprising a first polymer system comprising a conductive polymer non-homogenously entangled with a second polymer system comprising a polyanionic polymer.

18. An energy harvester, comprising an entangled polymer network comprising a first polymer system comprising a conductive polymer entangled with a second polymer system comprising a polyanionic polymer, wherein the conductive polymer and polyanionic polymer are phase separated.

19. An energy harvester, comprising an entangled polymer network comprising a first polymer system comprising a conductive polymer entangled with a second polymer system comprising a polyanionic polymer, wherein the entangled polymer network comprises a first portion comprising a high concentration of conductive polymer and low concentration of polyanionic polymer, and a second portion comprising a low concentration of conductive polymer and high concentration of polyanionic polymer.

20. The energy harvester of any one of claims 17-19, comprising a plurality of first portions and plurality of second portions.

21. The energy harvester of any one of claims 17-20, wherein the conducti ve polymer comprises a poly (thiophene), poly (aniline), poly (pyrrole), poly(carbazole), poly (azepine), or polyphenylene sulfide.2.

2. The energy harvester of any one of claims 17-21, wherein the conductive polymer comprises a poly (thiophene), or a combination thereof, preferably poly(3,4-propylenedioxythiophene) or poly(3,4-ethylenedioxythiophene).

23. The energy harvester of any one of claims 17-22, wherein the conductive polymer has the formula:Attorney Docket No. 10046-658W01wherein X is S, O, or NR, wherein R is H or Ci-4alkyl, R1and R2are independently choses from H, Ci-6alkyl, Ci-6alkoxy, Ci-6haloalkyl, Ci-6haloalkoxy, F, Cl, Br, I, CN, NO2, and wherein R1and R2, together with the two carbons to which they are attached, may form a five, six, or seven member ring.

24. The energy harvester of claim 23, wherein X is S, and R1and R2together form a six or seven-member ring, wherein said ring optionally has two oxygen atoms.

25. The energy harvester of any one of claims 17-24, wherein the polyanionic polymer comprises a poly-carboxylic acid, a poly-sulfonic acid, a poly-phosphonic acid, or a combination thereof.

26. The energy harvester of any one of claims 17-25, wherein the polyanionic polymer comprises a poly(acrylic acid), poly (methacrylic acid), poly(2-acrylamido-2-methyl-l-propanesulfonic acid), polystyrene sulfonic acid, polyvinyl sulfonic acid, polyvinylphosphonic acid, or a combination thereof.

27. The energy harvester of any one of claims 17-26, wherein the conductive polymer and the polyanionic polymer are present in a wt.% ration from 5:1 to 1:5, 5:1 to 1:1, from 5: 1 to 2.5: 1 from 4: 1 to 2: 1, from 2.5:1 to 1:2.5, from 2.5: 1 to 1: 1, from 1.5: 1 to 1:1.5, from 1.5:1 to 1:1, from 1:1 to 1:1.5, from 1:1 to 1:2.5, from 1:2 to 1:4, from 1:2.5 to 1:5, or from 1: 1 to 1:5, preferably from 1:2 to 1:4, or 1:2.5.

28. The energy harvester of any one of claims 17-27, exhibiting a lower electric potential than the otherwise same entangled polymer network that is not non-homogenously distributed, does not include a first and second portion, does not have phase separation, measured vs. Ag / AgCl under the same conditions.

29. The energy harvester of any one of claims 17-28, c.

30. The energy harvester of any one of claims 17-29, characterized by an x-ray diffraction pattern having a peak at about 0.38 °2θ.Attorney Docket No. 10046-658W0131. The energy harvester of any one of claims 17-30, characterized by an x-ray diffraction pattern having peaks at about 1.22 and about 0.38 °2θ, wherein the intensity of the peak at about 0.38 °2θ is greater than the peak at about 1.22 °2θ.

32. An electrochemical cell comprising the energy harvester according to any preceding claim in electrical communication with a first electrode, a second entangled polymer network in electrical communication with a second electrode, a separator disposed between the first and second energy harvesters.

33. The electrochemical cell according to claim 32, wherein the second entangled polymer network comprising the same polymers as the energy harvester, wherein said same polymers are not or less non-homogenously distributed, are not or less phase separated, or does not have or has less first and second portions.

34. The electrochemical cell according to any of claims 32-33, wherein the energy harvester has a lower electrical potential relative to the second entangled polymer network.

35. The electrochemical cell according to any of claims 32-34, wherein an x-ray diffraction pattern of the second entangled polymer network does not include a peak at about 0.38 °2θ.

36. The electrochemical cell according to any of claims 32-35, wherein the second entangled polymer network is characterized by an x-ray diffraction pattern having peaks at about 1.22 and about 0.38 °2θ, wherein the intensity of the peak at about 0.38 °2θ is less than the peak at about 1.22 °2θ.

37. The electrochemical cell according to any of claims 32-36, further comprising an electrolyte.

38. A battery, comprising at least one electrochemical cell according to any preceding claim.

39. The battery according to any preceding claim 38, comprising at least 5, at least 10, at least 20, at least 30, at least 40, or at least 50 electrochemical cells.

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