Lithium-ion capacitors (LICs), which combine great power and energy density, have become promising energy storage and have been well studied recently. Developing novel battery-type anode materials is the key to mitigating the kinetic mismatch between the anode and cathode electrodes. In this paper, niobium diboride (NbB₂) nanoparticles are synthesized via a salt-templated method and proposed for the first time as the anodes for LICs. NbB₂ is a layered two-dimensional material similar to graphite, which is favorable to the intercalation and deintercalation of Li⁺. The NbB₂ with high conductivity delivers outstanding long cycling stability (254.1 mAh g⁻¹ after 800 cycles at 0.1 A g⁻¹) and great rate capability. Moreover, a high-performance LIC is assembled employing the prepared NbB₂ as anode and commercialized activated carbon (AC) as cathode, which can display an energy density of 68.76 Wh kg⁻¹, a power density of 7.02 kW kg⁻¹, and a capacity retention ratio of 98% after 10,000 cycles. The work presents the great potential of transition metal borides as electrode materials and accelerates the development of LICs.

锂离子电容器（LIC）结合了巨大的功率和能量密度，已成为有前景的储能材料，并且最近得到了深​​入的研究。开发新型电池型负极材料是减轻阳极和阴极之间动力学失配的关键。在本文中，通过盐模板法合成了二硼化铌（NbB₂）纳米粒子，并首次提出作为LICs的阳极。NbB₂是一种类似于石墨的层状二维材料，有利于Li⁺。具有高电导率的NbB₂具有出色的长循环稳定性（在0.1 A g^-1-1）和出色的倍率性能。_{此外，采用制备的NbB 2}作为阳极和商业活性炭（AC）作为阴极组装了高性能LIC^-1，功率密度为7.02 kW kg^-1， 10000次循环后容量保持率为98%。这项工作展现了过渡金属硼化物作为电极材料的巨大潜力，并加速了LIC的发展。