Single crystalline fork-like potassium vanadate (K2V8O21) has been successfully prepared by electrospinning method with a subsequent annealing process. The as-obtained K2V8O21 forks show a unique layer-by-layer stacked structure. When used as cathode materials for lithium-ion batteries, the as-prepared fork-like materials exhibit high specific discharge capacity and excellent cyclic stability. High specific discharge capacities of 200.2 and 131.5 mA h g−1 can be delivered at the current densities of 50 and 500 mA g−1, respectively. Furthermore, the K2V8O21 electrode exhibits excellent long-term cycling stability which maintains a capacity of 108.3 mA h g−1 after 300 cycles at 500 mA g−1 with a fading rate of only 0.043% per cycle. The results demonstrate their potential applications in next-generation high-performance lithium-ion batteries.