锂离子电容器作为一种新型的混合储能器件，由于其兼具高能量密度和高功率密度而被广泛关注。其核心性能取决于正负极电极材料。炭基材料因其高导电性、优异的化学稳定性和可调控的孔隙结构，成为锂离子电容器LIC正负极材料的理想选择。煤气化细渣作为一种工业废弃物，经过分选去除大多数尾矿杂质之后所得富炭组分具有多孔结构和易于调控的特点，可作为良好的炭电极材料的前驱体。

本文以煤气化细渣为原料，经分选后得精炭，然后通过酸洗、活化、高温再炭化、杂原子掺杂等手段，分别制备了适用于锂离子电容器正、负极的电极材料。通过XRD、SEM、XPS、Raman、N₂吸脱附和TEM等结构表征及电化学性能研究，阐明其工艺-结构-性能之间的影响规律。主要研究内容及结果如下：

(1) 以煤气化细渣分选精炭为原料，采用酸洗脱灰、KOH活化，制备了多孔炭材料AC。当碱炭比为4时制备气化渣细基多孔炭AC-4具有最高比表面积2747.8 m² g^-1。在半电池测试中，AC-4在0.25 A g^-1电流密度下具有112.3 mAh g^-1的放电比容量，在1 A g^-1的电流密度下循环3000圈之后仍具有106%的容量保持率。AC-4作为正极材料，与商业硬碳CHC组装了LIC器件CHC//AC-4，在正负极活性物质比例为1.5时，表现出最高的能量密度和功率密度。当功率密度为321.0 W Kg^-1时，其能量密度为273.1 Wh kg^-1；在功率密度为6352.0 W kg^-1时，能量密度保持为79.4 Wh kg^-1。

       (2) 以分选精炭为原料，先经酸洗脱灰，然后分别经不同温度（900、1000、1100、1200和1300 ℃）炭化制备了气化细渣基硬碳材料HC。在1200 ℃炭化时制备所得HC-1200具有最佳的电化学性能。半电池测试中，HC-1200在0.1 A g^-1的电流密度下具有314.3 mAh g^-1的放电比容量，表现出最小的R_s（4.22 Ω）和R_ct（45.36 Ω）以及快的锂离子扩散系数。改变酸洗顺序：对分选精炭先炭化后酸洗，引入开孔后的气化细渣基硬碳HCS-1200的容量和锂离子扩散动力学有了进一步的提升，HCS-1200在0.1 A g^-1的电流密度下具有366.5 mAh g^-1的放电比容量，更小的R_s（2.31 Ω）和R_ct（16.75 Ω）以及更快的锂离子扩散系数。HCS-1200作为负极材料，与AC-4组装的LIC器件HCS-1200//AC-4，在6366.7 W kg^-1的高功率密度下仍具有152.1 Wh kg^-1的能量密度。电流密度在1 A g^-1下循环3000圈后的电容保持率为75.0%。

  (3) 以分选精炭为原料，只经盐酸酸洗，采用Ca₃(PO₄)₂作为掺杂剂，通过热还原反应制备了气化渣细基P掺杂硬碳PHC。当Ca₃(PO₄)₂添加量为0.2倍的酸洗精炭时，酸洗精炭中的SiO₂得到有效脱除，此时P的掺杂量为1.03%，所得PHC-0.2表现出最佳的电化学性能。PHC-0.2在0.1 A g^-1的电流密度下，放电比容量可达到388.2 mAh g^-1。在1 A g^-1的电流密度下循环1000圈之后容量并未出现衰减。LIC器件PHC-0.2//AC-4在330.1 W kg^-1功率密度下能量密度高达329.3 Wh kg^-1，在6222.8 W kg^-1的功率密度下具有121.0 Wh kg^-1的能量密度。1 A g^-1的电流密度下经3000圈循环后的电容保持率为82.1%。

As a novel hybrid energy storage device, lithium-ion capacitors have garnered significant attention due to their integration of high energy density and power density. The key performance metrics predominantly depend on the electrode materials employed in both positive and negative electrodes. Carbon-based materials emerge as an ideal candidate for lithium-ion capacitor electrodes owing to their exceptional electrical conductivity, superior chemical stability, and tunable porous architectures. Coal gasification fine slag, an industrial byproduct, demonstrates substantial potential as a precursor for carbon-based electrode materials. Following sorting processes that remove the majority of tailing impurities, the resultant carbon-rich component exhibits a well-developed porous structure, thereby fulfilling the essential requirements for electrode precursor materials.

In this paper, the electrode materials suitable for positive and negative electrodes of lithium ion capacitors were prepared by pickling, activation, high-temperature re-carbonization and heteroatom doping. Through XRD, SEM, XPS, Raman, N₂ adsorption and desorption and TEM, the structure characterization and electrochemical properties were studied, and the influence law between structure, property and process was clarified. The main research contents and results are as follows:

 (1) Porous carbon material AC was prepared from coal gasification fine slag separation carbon as raw material, acid elution ash and KOH activation. The AC-4 sample synthesized with KOH/C mass ratio of 4 exhibited the highest specific surface area of 2747.8 m² g^-1. In half-cell evaluations, AC-4 demonstrated a discharge specific capacity of 112.3 mAh g^-1 at 0.25 A g^-1and remarkable cyclic stability with 106% capacity retention after 3000 cycles at 1 A g^-1. When configured as a cathode material paired with commercial hard carbon (CHC) in a full-cell CHC//AC-4 system with an optimized active mass ratio of 1.5 (cathode:anode), the device achieved superior energy-power characteristics: delivering an energy density of 273.1 Wh kg^-1 at 321.0 W kg^-1 power density, while maintaining 79.4 Wh kg^-1 energy density even at an elevated power density of 6352.0 W kg^-1.

 (2) The gasified fine slag-based hard carbon material HC was prepared from separated refined carbon, and the ash was eluted by acid first, and then carbonized at different temperatures (900, 1000, 1100, 1200 and 1300 ℃). The obtained HC-1200 has the best electrochemical performance when carbonized at 1200 ℃. In the half-cell test, HC-1200 has a discharge specific capacity of 314.3 mAh g^-1 at a current density of 0.1 A g^-1, exhibiting the smallest R_s (4.22 Ω) and R_ct (45.36 Ω) and fast lithium ion diffusion coefficient. Change the pickling sequence: The capacity and lithium ion diffusion kinetics of the gasified fine slag-based hard carbon HCS-1200 introduced into the sorting refined carbon are further improved. HCS-1200 has a discharge specific capacity of 366.5 mAh g^-1, smaller R_s (2.31 Ω) and R_ct (16.75 Ω), and faster lithium ion diffusion coefficient at the current density of 0.1 A g^-1. HCS-1200 as the negative electrode material, and the LIC device HCS-1200//AC-4 assembled with AC-4 still has an energy density of 152.1 Wh kg^-1 at a high power density of 6366.7 W kg^-1. The capacitance retention after 3000 cycles at a current density of 1 A g^-1 was 75.0%.

 (3) Fine-based P-doped hard carbon PHC with gasified slag was prepared by thermal reduction reaction with sorted refined carbon as raw material, pickling with hydrochloric acid only, and using Ca₃(PO₄)₂ as dopant. When the Ca₃(PO₄)₂ addition reached 0.2 times the mass of acid-washed refined carbon, SiO₂ in the carbon was effectively removed , achieving a phosphorus doping level of 1.03%. Under this condition, PHC-0.2 exhibited optimal electrochemical performance. At a current density of 0.1 A g^-1, the discharge-specific capacity reached 388.2 mAh g^-1. Notably, no capacity decay was observed after 1000 cycles at 1 A g^-1. The PHC-0.2//AC-4 demonstrated an energy density of 329.3 Wh kg^-1 at a power density of 330.1 W kg^-1 and 121 Wh kg^-1 at 6222.8 W kg^-1. Furthermore, the capacitance retention rate remained 82.1% after 3000 cycles at 1 A g^-1.