Interface engineering based lignin-derived hollow carbon/nickel–cobalt–manganese layered double hydroxide composite structures for high-performance supercapacitors

Abstract

Interface engineering has emerged as a pivotal strategy to overcome the intrinsic limitations of transition metal layered double hydroxides (LDHs), particularly their severe restacking tendency and sluggish reaction kinetics in supercapacitor applications. Herein, we propose a heterointerface construction paradigm through the assembly of lignin-derived hollow carbon (LHC) spheres on pseudocapacitive nickel–cobalt–manganese LDH (NiCoMn-LDH) nanosheets via a facile co-precipitation methodology. The incorporation of LHC nanospheres serves as an effective separator to suppress the interlayer restacking of NiCoMn-LDH nanosheets while maximizing the accessibility of electroactive sites. Our density functional theory (DFT) calculations reveals the synergistic coupling between the faradaic NiCoMn-LDH and electric double-layer capacitive LHC, which endows the composite structure with exceptional charge storage characteristics; a specific capacity of 1144.60C g⁻¹ is achieved at 0.5 A g⁻¹, together with exceptional high-rate capability, which is evidenced by 74.80% capacity retention at 10 A g⁻¹. The engineered interface further mitigates structural degradation during cycling, enabling an asymmetric supercapacitor with a record-breaking energy density of 67.86 Wh kg⁻¹ at 399.99 W kg⁻¹ and superior cycle ability (the device retains 87.15% of its initial capacity after 10 000 charge–discharge cycles). This study provides fundamental insights into interfacial charge storage mechanisms for next-generation energy storage devices, in addition to establishing a sustainable pathway for biomass-derived carbon architectures.