Preparation And Electrochemical Performance Of Electrode Materials For Supercapacitors

Supercapacitors have excellent properties,widely used in electronic devices,communications and power vehicles.Electrode material is an important factor for supercapacitor performance.From the perspective of energy storage mechanism,the preparation of high performance electrode materials can be carried out by increasing the specific surface area of the material and increasing the probability of reversible oxidation reduction.Based on the current research,many reported high-performance electrode materials mostly need complex preparation technology and high cost but with low production.Therefore,the practical application is limited.In this paper,simple hydrothermal synthesis and solid phase sintering method are used to produce excellent electrode material.Main research contents of this paper are summaried as follows:?1?Mn₃O₄/Ni?OH?₂ nanocomposites are synthesized by a simply hydrothermal reaction under a temperature condition of 200 ?.In Mn₃O₄/Ni?OH?₂,the Mn³⁺ is doped in Ni?OH?₂,meanwhile the Ni2+ is doped in Mn₃O₄.The electrochemical properties of Mn₃O₄/Ni?OH?₂ are better than that of individual Ni?OH?₂ and Mn₃O₄ synthesized under the same preparation conditions,as well as the mechanical mixed composite of Mn₃O₄ and Ni?OH?₂.In 1 M KOH,the specific capacitance of Mn₃O₄/Ni?OH?₂ is 707 F/g at 1 A/g.After 2000 cycles,the specific capacitance can still be maintained 89%at 2 A/g.The Mn₃O₄/Ni?OH?₂ and commercial activated carbon were assembled into asymmetric capacitors,showing high energy density.The excellent electrochemical properties of Mn₃O₄/Ni?OH?₂ can be attributed to the synergistic effect of Mn₃O₄ and Ni?OH?₂,the co-existence of Mn₃O₄ and Ni?OH?₂ increase the probability of reversible redox reaction of electrode materials.Thus the Mn₃O₄/Ni?OH?₂ composite electrode is practical for pseudocapacitors.?2?Pure TiN nanoparticles were firstly synthesized in self-made stainless steel autoclaves by using Ti powder and NH₄Cl as raw materials under 530 ?.Using pyrrole as the carbon source,further reaction at 550 ? temperature,the N-doped TiN?TiN/C?were generated.The presence of carbon coating effectively impedes the contact of TiN between H2O and O₂ in electrolyte.In 1M KOH,TiN/C achieves 102.6 F/g at 1 A/g.After 5000 cycles,still retains a capacitance retention of 92%.Meanwhile,the TiN/C with a low operation voltage window,so will be a very valuable anode material for supercapacitors.The supercapacitors?TiN/C//MnO₂?assembled by TiN/C and MnO₂ shows excellent electrochemical properties.Compared with the supercapacitors?AC//MnO₂?assembled by commercial activated carbon and Mn02,TiN/C//MnO₂ possesses better specific capacitance and energy density.Therefore,the TiN/C is a promising negative material.?3?By a simple hydrothermal reaction,manganese silicate was obtained using one-step method under a temperature of 180 ?.After reaction for 3h,the sample posseses porous thin drapes structure,and shows a high specific surface area?439 m2/g?.In 1M KOH electrolyte,the specific capacitance is 288 F/g at 1 A/g.After 1000 cycles,the capacitance can be maintained 91.2%.Meanwhile,the supercapacitors constructed by manganese silicate and active carbon also demonstrate good power and energy density.Thus the manganese silicate will be a good new electrode material for supercapacitors.