Commercial Level Mass Loading Research Articles

High mass loading porous CoNi2S4 nanosheets with ultrahigh areal capacity for flexible supercapacitors

A commercial-level mass loading of a 3D porous network CoNi2S4 electrode with ultrahigh areal capacity was successfully achieved through the electrodeposition–hydrothermal two-step method.

High-mass-loading cobalt iron phosphide@nickel vanadium layered double hydroxide heterogeneous nanosheet arrays for hybrid supercapacitors

Designing multidimensional heterostructures on flexible substrates is an efficient approach to resolve the low energy density of supercapacitors. Herein, a three-dimensional (3D) porous cobalt iron phosphide (CoFeP)@nickel vanadium-layered double hydroxide (NiV-LDH) heterostructure has been prepared anchored on carbon cloth (CC) substrate. In this nanoarchitecture, NiV-LDH nanosheets are densely wrapped on the surface of CoFeP nanosheets, which forms a hierarchically porous framework with an enlarged surface area and accessible pore channels. Benefiting from the strong interaction and synergistic effect between CoFeP and NiV-LDH, the well-defined heterostructure can realize simultaneously rich redox active sites, rapid reaction dynamics, and good structural stability. Thus, the binder-free CoFeP@NiV-LDH electrode with a high mass loading of 6.47 mg cm−2 displays a significantly increased specific capacity of 903.1C g−1 (2.35C cm−2) at 1 A g−1 and enhanced rate capability when compared to pristine CoFeP and NiV-LDH. Additionally, the assembled hybrid supercapacitor (HSC) yields an energy density of 77.9 Wh kg−1/0.98 Wh cm−2 and excellent long-term stability. This research proposes a rational route for designing heterogeneous micro-/nanoarchitectures with commercial-level mass loading for the practical application of high-energy-density supercapacitors.

High-performance supercapacitor electrode at commercial-level mass loading from N-enriched activated carbon derived from soybean dregs

N-enriched activated carbons (ACs) are prepared via a facile triple-doping technique route. The self-doping from the precursor of soybean dregs and additional introduction from egg white guarantee a high-level of N contents in the Hydrothermal carbonization (HTC) products (biochar). With a KOH-activation, relatively high surface area and easy-accessible ion channels are constructed. A post-doping from the subsequent ammonia-activation compensates the loss of the N contents during the KOH-activation. Relatively high surface area of 1518 m2/g and N atomic fraction of 4.311 % are achieved. Taking advantage of the compaction density of 0.68 g/cm3, electrodes with commercial-level mass loading of ∼10 mg/cm2 are fabricated with a moderate thickness of ∼0.15 mm. With symmetric supercapacitors (SCs) of commercial-level electrodes, high values are achieved of 357.1 F/g in gravimetric capacitance and 235.7 F/cm3 in volumetric capacitance at 0.5 A/g are achieved in 1 mol/L H2SO4. With 1 mol/L Et4NBF4 in acetonitrile (AN) as electrolyte, the gravimetric capacitance is 246.2 F/g and volumetric capacitance is 162.5 F/cm3. Moreover, a high energy density of 44.27 Wh/kg delivered at a high power of 2656 W/kg, good rate capability and excellent long-term cycling stability make the N-enriched ACs a competitive candidate for practical applications.

Laser-induced manganese oxide/graphene composite electrodes with commercial-level mass loading towards high-performance supercapacitors

Combining of graphene with pseudocapacitance metal oxide is effective to construct supercapacitor electrode with high energy storage capacity. However, balancing the contradiction between high load of metal oxide and high stability of electrode is still challenging. Herein, a novel supercapacitor electrode composed of 3D graphene and manganese oxide is in-situ fabricated by laser carbonization of polyimide (PI) foam loaded with manganese acetate precursor. Due to the rich porous structure and super hygroscopicity of PI foam, high content manganese acetate is uniformly loaded into the network of PI foam. Under laser irradiation, PI foam is carbonized to form 3D porous graphene, while the generation of MnO-Mn3O4 and its uniform loading on graphene is achieved synchronously. The obtained composite electrode exhibits a commercial-level mass loading up to 8 mg cm−2, with a 48.6% weight ratio of MnO-Mn3O4. As a result, an ultra-high specific capacitance of 1525 mF cm−2 can be obtained for the composite electrode at the optimal doping concentration of 0.3 mol L− 1. Notably, the composite electrode also exhibits excellent cycling stability of 94.75% retention rate after 6000 cycles. The maximum area specific capacitance of the micro supercapacitor with PVA/LiCl gel electrolyte is 410.19 mF cm−2, the maximum energy density and power density are 82.04 μWh cm−2 and 400 μW cm−2, respectively.

High performance supercapacitors based on WS2 nanoflower electrodes with commercial-level mass-loading

Supercapacitors with a commercial-level mass loading of active materials are designed to offer greater energy storage capacity than conventional supercapacitors. For the first time, we are reporting the fabrication and performance studies of a symmetric supercapacitor with 30 mg cm−2 commercial-level mass loading of 2D WS2 nanoflower electrode material, which exhibited superior electrochemical performance. At 5 mV s–1 specific capacitance achieved by the device is 204 F g–1. At 1 A g–1, the supercapacitor provides impressive specific energy and power values of 14 Wh kg−1 and 0.8 kW kg−1, respectively. The device maintains an exceptional cycling stability of 100 % over 10,000 cycles of continuous charging and discharging. Furthermore, supercapacitor coin cells fabricated using commercial-level-mass loaded 2D WS2 electrodes are used to power an LED.

Corn-straw-converted activated carbons with tunable porosity and N/O functionalities as high-performance supercapacitors electrode at commercial-level mass loading

With the scientific importance and industrial need for low-cost but high-performance activated carbons (ACs) for supercapacitors (SCs), ACs with tailorable porous texture and heteroatom doping are turned from corn straw via hydrothermal and activation processes. Porous texture is mainly adjusted by KOH/biochar mass ratio. O and N surface functionalities are tuned by a subsequent high-temperature treatment by H2O or ammonia. The influences of porosity in the amounts of the introduced N contents are investigated. With symmetric SC cells, the electrochemical performances of the corn-straw-derived ACs are examined at commercial-level mass loading. For aqueous electrolyte, the ACs prepared without KOH activation but with high-temperature treatment by ammonia exhibit high gravimetric capacitance of 192 F/g and volumetric capacitance of 150 F/cm3 due to their high compact density and N atomic fraction. For organic system, the optimum ACs are activated with KOH/biochar ratio of 1:1 and a subsequent ammonia high-temperature treatment, which deliver high gravimetric capacitance of 258 F/g and volumetric capacitance of 167 F/cm3. Balanced porosity and density, low O fraction but high N fraction are found to be favored for organic system. The cost-effective technique route may provide guidance for the design and preparation of biomass-derived ACs with tunable porosity and heteroatom functionalities for practical applications in SCs.

Dual-Ion Co-intercalation Mechanism on a Na2V6O16·3H2O Cathode with a Commercial-Level Mass Loading for Aqueous Zinc-Ion Batteries with High Areal Capacity.

A proton (H+) and zinc ion (Zn2+) co-insertion model is put forward in this study to elucidate the capacity origin of an aqueous zinc ion battery (ZIB) based on a heavily loaded (∼15 mg cm-2) cathode, which consists of Na2V6O16·3H2O (NVO) embedded particularly in the macropores of activated carbon cloth (ACC), coupled with a highly stable Zn/In anode. The confinement effect of these porous channels not only prevents the detachment of NVO from ACC but also well mitigates its volume change resulting from H+ and Zn2+ co-intercalation, which collectively render the stability of NVO/ACC markedly enhanced. Moreover, the bicontinuous structure of NVO/ACC, as a result of the self-interlacing of intrapore NVO, which is first engineered into the nanobelts, and their interlocking with the carbon fibers of ACC, simultaneously giving rise to a solid and a holey framework, is favorable to the electron and ion transport throughout the entire electrode. The synergistic effect of such facile charge transfer kinetics and the high packing density of NVO in the cathode endows ZIBs with not only a good rate performance but also an exceptional areal capacity amounting to 4.6 mAh cm-2, far surpassing those reported for additional vanadium-based counterparts reported in the literature.

Explosive effect-assisted synthesis of hierarchical porous carbon for high-performance aqueous Zn-ion hybrid supercapacitors with commercial level mass loading

Aqueous Zn-ion hybrid supercapacitors (AZHCs) are potential types of energy storage applications that combine the advantages of supercapacitors and batteries. The low mass loading and poor rate performance of cathodes, however, severely limits their practical application. Herein, an explosive effect assisted strategy is reported for the efficient synthesis of N, O co-doped porous carbon nanosheets (NPCNs) by synergistic activation of high-quality soft carbon precursor perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) with KOH and Zn(NO3)2. Benefiting from the comprehensive modulation of the morphology, pore structure, and surface chemistry, the obtained NPCNs show the significant enhancement in diffusion kinetics. Consequently, the as-fabricated AZHCs exhibited remarkably improved Zn-ion storage capability (189.3 mAh g−1 at 0.1 A g−1, 96.7 mAh g−1 at 20 A g−1) and long-term cycling stability at 20 A g−1 (∼ 92.5 % retention upon 6000 cycles). Moreover, NPCNs also deliver a superb areal capacity of 1.6 mAh cm−2 with a mass loading of 15.4 mg cm−2. Most importantly, we demonstrate that such porous carbon framework with competent electrochemical properties can be easily produced from diverse soft carbon precursor. This work thus introduces a universal and efficient strategy to produce high-performance porous carbon electrode materials for AZHCs.

High Mass Loading of Flowerlike Ni-MoS2 Microspheres toward Efficient Intercalation Pseudocapacitive Electrodes

This work reports the exploration of intercalation pseudocapacitance in a thicker electrode of flowerlike Ni-doped MoS2 microspheres that features a mass loading of ∼10 mg/cm2 without sacrificing the gravimetric capacitance (∼425 F/g at 5 mV/s). Integration of Ni atoms into MoS2 microspheres not only stabilized the structural integrity but also ameliorated the rapid intercalation and deintercalation of electrolyte ions even at a commercial-level mass loading. The energy instability by Ni doping significantly changed the local bonding behavior and the overall electronic structure of MoS2, facilitating the breaking of the MoS2 layer and generation of more active edge sites, which are responsible for faster reaction kinetics. The experiments attribute the overall capacitance enhancement in (Mo-Ni)S2 to the increased rate of electrolyte ion insertion and extraction, which is confirmed by b-values close to 0.5, at different potentials, indicating that the current response predominantly depends on the diffusive mechanism for both MoS2 and Ni-MoS2 thicker electrodes. The symmetric device constructed with Ni-MoS2 microspheres exhibited a capacitance value of 101 F/g in 1 mV/s, for which the energy density is 9 Wh/kg, as well as attained an outstanding cycling stability of 10 000 cycles with 60% retention at 2 A/g. In addition to providing insights into the development of 2D TMDs, this work explores the design of robust and highly efficient intercalation electrode material for electrochemical energy storage devices.

Fermentation assisted preparation of O and N riched porous carbon for high performance flexible supercapacitors

Microorganisms have a superior biodegradability on biomass carbon. Herein, active yeast fermented cottonseed meal (FCM) by used as carbon precursor and K2CO3 as activator to prepare high O and N-doped porous carbon. The fermentation process not only decomposes the structural units of CM but also creates pore structure and increases the O, N group of the fermented CM (FCM). Most importantly, fermentation can improve the activation efficiency of K2CO3 and enhance the oxygen content. The optimized FCM-700-2 exhibits high O (19.45 at%) and N (3.13 at%) contents and hierarchical porous structure. The specific capacitance can reach up to 384 F g-1 in 6 M KOH. What’s more, we prepare a novel potassium citrate-agar gel electrolyte (PCA) with high operating voltage. The flexible symmetrical capacitor assembled with a commercial level mass loading of FCM-700-2 and PCA gel electrolyte delivers a high energy density of 27.4 Wh kg-1. Meanwhile, more than 109% of initial specific capacitance retains after 12, 000 cycles. This study provides a fermentation assisted strategy to prepare porous carbon materials, which has the advantage of simple, efficient, low activator ratio and high heteroatoms contents.

Improving the intrinsic conductivity of δ-MnO2 by indium doping for high-performance neutral aqueous sodium-ion supercapacitors with commercial-level mass-loading

Indium is introduced to δ-MnO2 for the first time. The conductivity of δ-MnO2 can be doubled and a high specific capacity can be achieved at a commercial-level mass loading.

Design of high-mass loading metal–organic framework-based electrode materials with excellent redox activity for long-lasting electrochemical energy storage applications

Nowadays, metal–organic framework-derived (MOF-D) materials are auspicious in various research areas due to their beneficial traits of diverse structural features, large surface area, and high porous nature. Herein, we report the MOF-D nickel–cobalt terephthalate hydroxides (Ni-Co THs) via a one-pot solvothermal approach without further annealing. Direct growth of active materials on conductive substrates (e.g., nickel foam (NF)) can potentially eliminate the use of sluggish and non-conductive binders, leading to enhanced redox chemistry with commercial-level mass loading (8–10 mg cm−2). All the binder-free MOF-D Ni-Co TH electrodes demonstrated excellent areal capacities at the same current density of 3 mA cm−2. Among them, the Ni-Co TH-160/9h electrode delivered a superior areal capacity/specific capacity of 2087 µAh cm−2/200.68 mAh g−1 at 3 mA cm−2, together with outstanding cycling retention of 100 % after 20,000 charge–discharge cycles. The achieved ultrahigh performance is ascribed to the synergistic properties of Ni-Co THs, three-dimensional porous NF, and morphological structures. Utilizing the charge storage performance of the Ni-Co TH-160/9h electrode, an electrochemical cell (ECC) was assembled. The as-assembled ECC delivered good areal capacity (1678.6 µAh cm−2), energy density (1.3 mWh cm−2), and power density (48.6 mW cm−2) with outstanding cycling performance (35,000 cycles (99.9 %)). Also, the ECC verified its energy storage properties by powering various portable electronic appliances.

Direct growth of porous vanadium nitride on carbon cloth with commercial-level mass loading for solid-state supercapacitors

Mass production of wearable devices with effective three-dimensional (3D) structure is a vital prerequisite for practical energy storage. Vanadium nitride (VN) has been identified as a promising supercapacitor electrode due to its wide negative potential working window, high specific capacitance and outstanding electrical conductivity, Herein, porous VN is grown on carbon cloth (CC) by a dip-coating and nitridation method. Such a VN/CC electrode provides effective 3D structure is beneficial for high mass loading (up to 28.3 mg cm−2) with high specific capacitance. Consequently, the as-prepared VN/CC electrode can achieve high areal capacitance of 3.34 F cm−2 at 5 mA cm−2. As a result, the flexible symmetric supercapacitor shows robust cycling stability (96% retention over 10,000 cycles) with PVA/KOH gel electrolyte. In addition, high energy/power density (0.341 mWh cm−2 at 1.92 mW cm−2) and excellent cycling performance (87% retention over 8000 cycles) are achieved in the assembled solid-state asymmetric supercapacitor cell with Zn−Ni−Co ternary oxides (ZNCO)/NF cathode and VN/CC anode. The results provide a simple route to prepare high mass loading porous VN-based electrodes with outstanding areal capacitance. It is believed that this strategy will favor the development of other transition metal nitride electrodes for commercial use in the future.

Compact 3D Metal Collectors Enabled by Roll-to-Roll Nanoimprinting for Improving Capacitive Energy Storage.

Reducing the contact resistance between active materials and current collectors is of engineering importance for improving capacitive energy storage. 3D current collectors have shown extraordinary promise for reducing the contact resistance, however, there is a major obstacle of being bulky or inefficient fabrication before they become viable in practice. Here a roll-to-roll nanoimprinting method is demonstrated to deform flat aluminum foils into 3D current collectors with hierarchical microstructures by combining soft matter-enhanced plastic deformation and template-confined local surface nanocracks. The generated 3D current collectors are inserted by and interlocked with active electrode materials such as activated carbon, decreasing the contact resistance by at least one order of magnitude and quadrupling the specific capacitance at high current density of 30 A g-1 for commercial-level mass loading of 5mg cm-2 . The 3D current collectors are so compact that they have a low volume percentage of 7.8% in the entire electrode film, resulting in energy and power density of 29.1Wh L-1 and 12.8kW L-1 , respectively, for stack cells in organic electrolyte. Furthermore, roll-to-roll nanoimprinting of metal microstructures is low-cost, high-throughput, and can be extended to other systems that involve the microstructured metal interface, such as batteries and thermal management.

Direct Growth of Porous Vanadium Nitride on Carbon Cloth with Commercial-Level Mass Loading for High-Performance Solid-State Supercapacitors

Direct Growth of Porous Vanadium Nitride on Carbon Cloth with Commercial-Level Mass Loading for High-Performance Solid-State Supercapacitors

Ultrasound-assisted facile one-pot synthesis of ternary MWCNT/MnO2/rGO nanocomposite for high performance supercapacitors with commercial-level mass loadings

Commercial application of supercapacitors (SCs) requires high mass loading electrodes simultaneously with high energy density and long cycle life. Herein, we have reported a ternary multi-walled carbon nanotube (MWCNT)/MnO2/reduced graphene oxide (rGO) nanocomposite for SCs with commercial-level mass loadings. The ternary nanocomposite was synthesized using a facile ultrasound-assisted one-pot method. The symmetric SC fabricated with ternary MWCNT/MnO2/rGO nanocomposite demonstrated marked enhancement in capacitive performance as compared to those with binary nanocomposites (MnO2/rGO and MnO2/MWCNT). The synergistic effect from simultaneous growth of MnO2 on the graphene and MWCNTs under ultrasonic irradiation resulted in the formation of a porous ternary structure with efficient ion diffusion channels and high electrochemically active surface area. The symmetric SC with commercial-level mass loading electrodes (∼12 mg cm−2) offered a high specific capacitance (314.6 F g−1) and energy density (21.1 W h kg−1 at 150 W kg−1) at a wide operating voltage of 1.5 V. Moreover, the SC exhibits no loss of capacitance after 5000 charge−discharge cycles showcasing excellent cycle life.

Nickel salts-induced microstructure modification of B–N co-doped porous carbons for high-performance supercapacitor electrodes

Herein, we report a facile strategy for microstructure modification of B–N co-doped porous carbons induced by nickel salts. Nickel chloride mainly plays a pore-forming role in the formation of resultant BNHC-L, leading to a high surface area (SSA) of 1000 m2 g−1, and favors high-level heteroatom doping and enhancement of graphitization degree simultaneously. Contrastively, nickel acetate facilitates the generation of Ni–B–N multi-doping porous carbon (BNHC-Y) but seriously hinders the fabrication of nanopores. BNHC-L exhibits superior specific capacitance of 342 F g−1 at 0.5 A g−1 in the three-electrode system due to higher SSA and heteroatom content, and enhanced electrical conductivity than BNHC-Y. BNHC-Y shows better rate performance with a capacitance retention of 60.4% from 0.5 to 100 A g−1 based on its higher mesopore ratio and better wettability than BNHC-L. Notably, as supercapacitor electrode with commercial-level mass loading (~180 µm, ~13 mg cm−2), BNHC-L2Y2 prepared with the dual nickel salts can deliver a high specific capacitance of 245 F g−1 at 0.05 A g−1, superior capacitance retention of 86.1% at 5 A g−1, and excellent cycling stability (94.8% of its initial specific capacitance after 10,000 cycles) because of its considerable SSA, optimal PSD, suitable surface chemistry and enhanced electrical conductivity.

Superior capacitive storage behavior of porous carbon electrode with high mass loading

Porous carbon (PC) derived from the petroleum pitch via the template-guidance coupled with activation methodology, possesses hierarchical pore structure in view of micropore and mesopore. As the electrode material for electrochemical double-layer capacitor, PC electrode not only possesses the good adaptability to aqueous and organic electrolytes, but also delivers the superior capacitive behavior with respect to capacitance and rate capability over those of counterparts (activation-derived carbon and commercial activated carbon). Furthermore, relatively high values of gravimetric and areal capacitances (247F g−1 and 2470 mF cm−2) can be guaranteed simultaneously for PC electrode even at the commercial-level mass loading of 10 mg cm−2, demonstrating the good compatibility to gravimetric and areal capacitances. The satisfactory capacitive storage behavior of PC is ascribed to the synergistic effect of hierarchical pore structure and extraordinary structural integrity. Besides, this work also presents a high value-added utilization strategy to prepare the high-performance porous carbon-based electrode material for capacitive energy storage.

Microporous carbon derived from anthracite as supercapacitor electrodes with commercial level mass loading

Porous carbon is considered as an ideal electrode material for supercapacitor applications. Meanwhile, converting coal into cleaner energy storage materials accords with the concept of green development nowadays. Herein, microporous carbons derived from anthracite (AMCs) were prepared via a simple KOH activation, which possess ultrahigh specific surface area (up to 2947 m2 g−1), developed pore structure (1.473 cm3 g−1 total pore volume) and considerable yield (≥42.3%). The optimized sample (AMC800) achieves largest micropore volume (0.947 cm3 g−1) and superior conductivity (976.56 S m−1). Therefore, AMCs reveals excellent electrochemical performances as electrode material with commercial level mass loading (∼10±0.5 mg cm−2). In aqueous electrolyte, the assembled SCs present outstanding specific capacitance (up to 282 F g−1 at 0.5 A g−1) and high rate performance (87.23% at 10 A g−1). For organic system, AMC800-based SC delivers superior energy density (34.08 Wh kg−1) and remarkable cycling stability (93.45% retention after 10,000 cycles), which are superior to supercapacitor grade commercial carbon (YP-50F). Hence, this work is significant to the actual production of coal-based porous carbon and its commercial application as supercapacitors electrode material.

From powders to freestanding electrodes: Assembly active particles into bacterial cellulose for high performance supercapacitors

The assembly of powdered materials into freestanding electrodes can avoid the usage of metallic current collectors and thus reduce the weight and cost of devices. In this work, we prepared robust, binder-free freestanding membrane electrodes consisting of a three-dimensional network of bacterial cellulose (BC) with acetylene black and activated carbon uniformly embedded. Filtration as a facile method was employed to prepare the highly hydrophilic and conductive porous network. This architecture facilitated electrolyte infiltration and significantly enhanced the electrolyte uptake (6 times of the entire electrode weight), which subsequently improved ion transport and reduced the contact resistance between electrode and electrolyte. Owing to the high porosity, excellent wettability and the efficient utilization of active material, the obtained freestanding electrode with a mass loading of 3 mg cm−2 delivered a high capacity of 276 F g−1 at 1 A g−1. It also exhibited an excellent cycle stability at 5 A g−1 without detectable capacity fading after 10,000 cycles in a two-electrode system. More importantly, a high specific capacitance of 167 F g−1 at 1 A g−1 and a high energy density of 5.3 W h kg−1 at 163 W kg−1 with respect to the overall weight of electrode were achieved at a commercial level mass loading of 10 mg cm−2, which considerably outperformed common electrode using nickel foam as current collector. This work provided a facile and effective way in producing lightweight, low cost and high-performance electrodes.