Controlling the Effective Surface Area and Pore Size Distribution of sp 2 Carbon Materials and Their Impact on the Capacitance Performance of These Materials Long Zhang, Xi Yang, Fan Zhang, Guankui Long, Tengfei Zhang, Kai Leng, Yawei Zhang, Yi Huang, Yanfeng Ma, Mingtao Zhang, and Yongsheng Chen* The Key Laboratory for Functional Polymer Materials and Centre for Nanoscale Science and Technology, Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China * S Supporting Information ABSTRACT: A series of sp 2 carbon materials with different specific surface area (SSA) and controlled pore size distribution (PSD) were synthesized at large scale through a facile and low-cost method. The SSA and PSD of these carbon materials were controlled by using different carbon sources and preparation methods. With different total and effective SSA (E-SSA) and PSD, the impacts on their capacitance performance were investigated thoroughly, which demonstrated that both E-SSA and PSD played the most important roles in their capacitance performance. Furthermore, theoretical modeling was performed, and the results are in agreement with the experimental results for the influence of E-SSA and PSD on their capacitance performance. Based on these, a general model using the slit/cylindrical NL-DFT approach is proposed for the estimation of the specific capacitance of sp 2 carbon materials, which offers a simple but reliable method to predict the capacitance performance of these materials, thus speeding up the design and screening of the materials for high-performance supercapacitor and other surface area related devices. ■ INTRODUCTION Supercapacitors based on sp 2 carbon materials have attracted tremendous attention in both theoretical and practical application studies for their high power density, superior performance in extreme temperatures, and outstanding cycle stability. 1-6 During the past several years, most efforts have been focusing on increasing the specific capacitance and operating voltage of carbon-based supercapacitors to achieve higher energy density, 1,7 which can make carbon-based supercapacitors more capable for the primary power sources to replace batteries. 8-10 Since the operating voltage is simply determined/limited by the electrolytes 1,11 but the specific capacitance of carbon materials is more complicated and dependent on many factors such as specific surface area (SSA), pore size distribution (PSD) and conductivity of carbon materials, thus more efforts have been devoted on increasing specific capacitance of carbon materials, such as using carbon materials with high SSA ranging from ∼1000 to more than 3000 m 2 /g. 2,8,9,12-17 However, for those high surface area materials used for supercapacitor applications, such as that based on the activated carbon (AC) materials, 18-20 total SSA is unfortunately but generally used and discussed for their capacitance performance. This unavoidably often gives wrong impression since it is the effective specific surface area (E-SSA) which is accessible to the electrolyte ions and eventually determines the fundamental performance. 11,21 As we know, the E-SSA is determined by both the total SSA and the PSD of carbon materials based on the electrolyte ion sizes. 9 Therefore, thorough investigation is much needed to explore the controlling of both SSA and PSD of sp 2 carbon-based materials for more effective material design with better capacitance performance. Indeed, some elegant works have been reported in this regard using the carbon materials prepared from template approach for studying the influence of SSA and PSD on the capacitance Received: March 12, 2013 Published: March 28, 2013 Article pubs.acs.org/JACS © 2013 American Chemical Society 5921 dx.doi.org/10.1021/ja402552h | J. Am. Chem. Soc. 2013, 135, 5921-5929