<p>Increasing the interlayer spacing of metal–organic frameworks (MOFs) through multi-metal ion doping has emerged as an effective strategy to enhance electrolyte-ion transport within the MOF unit cell, enabling the design of nickel-based MOF materials with high capacity and energy density. In this work, a series of NiCo-MOF-<i>x</i> (<i>x</i> = 1–5) were synthesized by incorporating Co<sup>2+</sup> ions into Ni-MOF. The introduction of Co<sup>2+</sup> modulated the unit cell structure and governed the stacking configuration of MOF nanosheets. At an optimal Ni/Co molar ratio of 4:1, the NiCo-MOF-2 sample demonstrates superior electrochemical performance, delivering a specific capacitance of 1238.6 F g<sup>−1</sup> at 0.2 A g<sup>−1</sup>. Subsequently, NiCo-MOF-2 was grown in situ on carbonized wood (CW) to fabricate a NiCo-MOF@CW composite, which exhibits an areal capacitance of 4960 mF cm<sup>−2</sup> at 0.6&#xa0;mA&#xa0;cm<sup>−2</sup>. An asymmetric supercapacitor (NiCo-MOF@CW//AC) was assembled using NiCo-MOF@CW as the positive electrode and activated carbon (AC) as the negative electrode. The device achieves an areal energy density of 1.88 mWh cm<sup>−2</sup> at a power density of 2.88 mW cm<sup>−2</sup> (1&#xa0;mA&#xa0;cm<sup>−2</sup>), with 83.6% capacitance retention after 2000 charge–discharge cycles. Notably, two serially connected NiCo-MOF@CW//AC devices successfully illuminate a red LED (operating voltage: 1.6–1.75&#xa0;V) for 20&#xa0;min. The multi-metal ion doping strategy combined with binder-free, self-supporting electrode architecture presents a novel approach for synthesizing high-performance energy storage materials.</p> Graphical abstract <p></p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Ni, Co bimetallic MOF of dual-controlled by micro-morphology and unit cell structure for biomass-based self-supporting energy storage device

  • Yongkang Zhang,
  • Chuanyin Xiong,
  • Qiancheng Xiong,
  • Qing Xiong,
  • Mengjie Zhao,
  • Bo Wang,
  • Mengxia Shen,
  • Qiusheng Zhou,
  • Yonghao Ni

摘要

Increasing the interlayer spacing of metal–organic frameworks (MOFs) through multi-metal ion doping has emerged as an effective strategy to enhance electrolyte-ion transport within the MOF unit cell, enabling the design of nickel-based MOF materials with high capacity and energy density. In this work, a series of NiCo-MOF-x (x = 1–5) were synthesized by incorporating Co2+ ions into Ni-MOF. The introduction of Co2+ modulated the unit cell structure and governed the stacking configuration of MOF nanosheets. At an optimal Ni/Co molar ratio of 4:1, the NiCo-MOF-2 sample demonstrates superior electrochemical performance, delivering a specific capacitance of 1238.6 F g−1 at 0.2 A g−1. Subsequently, NiCo-MOF-2 was grown in situ on carbonized wood (CW) to fabricate a NiCo-MOF@CW composite, which exhibits an areal capacitance of 4960 mF cm−2 at 0.6 mA cm−2. An asymmetric supercapacitor (NiCo-MOF@CW//AC) was assembled using NiCo-MOF@CW as the positive electrode and activated carbon (AC) as the negative electrode. The device achieves an areal energy density of 1.88 mWh cm−2 at a power density of 2.88 mW cm−2 (1 mA cm−2), with 83.6% capacitance retention after 2000 charge–discharge cycles. Notably, two serially connected NiCo-MOF@CW//AC devices successfully illuminate a red LED (operating voltage: 1.6–1.75 V) for 20 min. The multi-metal ion doping strategy combined with binder-free, self-supporting electrode architecture presents a novel approach for synthesizing high-performance energy storage materials.

Graphical abstract