TY - JOUR
T1 - Urea-Assisted Nickel-Manganese Phosphate Composite Microarchitectures with Ultralong Lifecycle for Flexible Asymmetric Solid-State Supercapacitors
T2 - A Binder-Free Approach
AU - Katkar, Pranav K.
AU - Patil, Supriya A.
AU - Jeon, Jae Ho
AU - Na, Hong Ryeol
AU - Padalkar, Navnath S.
AU - Jerng, Sahng Kyoon
AU - Lee, Sunghun
AU - Chun, Seung Hyun
N1 - Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/11/3
Y1 - 2022/11/3
N2 - The limited energy density and cyclability of supercapacitors are major roadblocks to their development as energy storage devices. To address these issues, a binder-free nickel-manganese (Ni-Mn) phosphate composite (NMP series) microarchitecture has been synthesized by the hydrothermal method on a nickel foam (NF) substrate using various urea dosages. Due to the influence of urea, microrod-/microplate-like morphologies of NMP series thin films evolved to micropetals. This study demonstrates a synergy between Ni and Mn metal ions and also the influence of different urea contents on the physicochemical properties of mesoporous NMP series thin films. Notably, the NMP-4 microarchitecture has a large surface area (7.5 m2g-1), which provides more electroactive sites in electrochemical measurements. Accordingly, in the NMP series electrodes, the NMP-4 thin film demonstrated high electrochemical properties (the maximum specific capacity was found to be 901 C/g at a 5 mV/s scan rate) and retained 127% capacity over 6000 cycles, indicating good durability with a well-preserved microstructure throughout the cycling. Furthermore, a flexible asymmetric solid-state (FASS) supercapacitor was designed utilizing NMP-4 and reduced graphene oxide (rGO) as a cathode and an anode, respectively, in the poly(vinyl alcohol)-KOH (PVA-KOH) gel electrolyte with an extended operational voltage of +1.8 V. This FASS device provides a high specific capacity (192 C/g at 0.6 A/g current density), supreme energy density (48.2 Wh kg-1) at a power density of 575 W kg-1, and a desirable longevity of 108% over 5000 cycles. Moreover, the FASS device also demonstrated its practical applicability. The long-term stability suggests that the binder-free urea-assisted Ni-Mn phosphate composite is a good candidate for energy storage devices.
AB - The limited energy density and cyclability of supercapacitors are major roadblocks to their development as energy storage devices. To address these issues, a binder-free nickel-manganese (Ni-Mn) phosphate composite (NMP series) microarchitecture has been synthesized by the hydrothermal method on a nickel foam (NF) substrate using various urea dosages. Due to the influence of urea, microrod-/microplate-like morphologies of NMP series thin films evolved to micropetals. This study demonstrates a synergy between Ni and Mn metal ions and also the influence of different urea contents on the physicochemical properties of mesoporous NMP series thin films. Notably, the NMP-4 microarchitecture has a large surface area (7.5 m2g-1), which provides more electroactive sites in electrochemical measurements. Accordingly, in the NMP series electrodes, the NMP-4 thin film demonstrated high electrochemical properties (the maximum specific capacity was found to be 901 C/g at a 5 mV/s scan rate) and retained 127% capacity over 6000 cycles, indicating good durability with a well-preserved microstructure throughout the cycling. Furthermore, a flexible asymmetric solid-state (FASS) supercapacitor was designed utilizing NMP-4 and reduced graphene oxide (rGO) as a cathode and an anode, respectively, in the poly(vinyl alcohol)-KOH (PVA-KOH) gel electrolyte with an extended operational voltage of +1.8 V. This FASS device provides a high specific capacity (192 C/g at 0.6 A/g current density), supreme energy density (48.2 Wh kg-1) at a power density of 575 W kg-1, and a desirable longevity of 108% over 5000 cycles. Moreover, the FASS device also demonstrated its practical applicability. The long-term stability suggests that the binder-free urea-assisted Ni-Mn phosphate composite is a good candidate for energy storage devices.
UR - http://www.scopus.com/inward/record.url?scp=85140853169&partnerID=8YFLogxK
U2 - 10.1021/acs.energyfuels.2c02875
DO - 10.1021/acs.energyfuels.2c02875
M3 - Article
AN - SCOPUS:85140853169
SN - 0887-0624
VL - 36
SP - 13356
EP - 13369
JO - Energy and Fuels
JF - Energy and Fuels
IS - 21
ER -