Excellent Performance of Few‐Layer Borocarbonitrides as Anode Materials in Lithium‐Ion Batteries

Borocarbonitrides (B x C y N z ) with a graphene‐like structure exhibit a remarkable high lithium cyclability and current rate capability. The electrochemical performance of the B x C y N z materials, synthesized by using a simple solid‐state synthesis route based on urea, was strongly dependent on the composition and surface area. Among the three compositions studied, the carbon‐rich compound B 0.15 C 0.73 N 0.12 with the highest surface area showed an exceptional stability (over 100 cycles) and rate capability over widely varying current density values (0.05–1 A g −1 ). B 0.15 C 0.73 N 0.12 has a very high specific capacity of 710 mA h g −1 at 0.05 A g −1 . With the inclusion of a suitable additive in the electrolyte, the specific capacity improved drastically, recording an impressive value of nearly 900 mA h g −1 at 0.05 A g −1 . It is believed that the solid–electrolyte interphase (SEI) layer at the interface of B x C y N z and electrolyte also plays a crucial role in the performance of the B x C y N z .