Monolithic three‐dimensional hollow nanoporous Cu_xO encapsulated mesoporous Cu heterostructures with superior Li storage properties

Abstract

Drastic volume expansion and low conductivity are critical factors leading to severe capacity decay of transition metal oxides (TMOs) as anodes for lithium‐ion batteries (LIBs). An effective strategy to overcome this challenge is to engineer freestanding 3D hollow architectures integrated with nanostructured metals to boost their structural stability and electrical conductivity simultaneously. Inspired by cowpea configuration beneficial to improve the transport of rich water in arid environment, herein, a novel monolithic 3D hollow nanoporous CuxO encapsulated mesoporous Cu heterostructure (3D‐HNP CuxO@m‐Cu) is delicately designed and fabricated via a simple three‐step approach. Compared to other CuxO‐based electrodes with different structure designs in published reports, the unique 3D‐HNP CuxO@m‐Cu as a binder‐free integrated anode for LIBs shows superior Li storage properties with first reversible capacity of 2.02 mAh cm−2 and good cycling stability with 76.2% capacity retention and 99.9% coulombic efficiency after 200 cycles. This can be largely attributed to the unique 3D nanoporous heterostructure design with a synergistic effect between interconnected hollow CuxO nanotubes with bidirectional mechanical stress buffer and internal mesoporous Cu network with enhanced electrical conductivity. We believe that this work provides a brand‐new strategy for rational design and fabrication of next‐generation high‐performance TMOs‐based anodes toward advanced LIBs.

Stress-Relief Engineering in a N-Doped C-Modified Hierarchical Nanoporous Si Anode with a Microcurved Pore Wall Structure for Enhanced Lithium Storage

“…Also, the other two peaks are associated with the bonds of Si–Si (99.79 eV) and Si–C (102.48 eV). In Figure e, a set of fitted peaks match the C–O, Si–O, and CO bonds (530.84, 532.76, and 533.04 eV), respectively. ,,, The peaks in the D (1366 cm –1 ) and G (1594 cm –1 ) bands in the Raman spectrum of N-C@m-HNP Si (Figure f) correspond to disordered carbon and graphitic carbon, respectively. − The intensity ratio between peaks D and G ( I D / I G ) indicates the degree of graphitization of the carbon. , The higher the I D / I G value, the more disordered the carbon is and the poorer the crystallinity. The I D / I G of the carbon layer formed by polydopamine carbonization is 0.851, indicating that it has a significant degree of disorder.…”

“…Silicon (Si) is considered a promising candidate for anodes in lithium-ion batteries due to its high theoretical specific capacity (3579 mAh g –1 ) at room temperature and abundant natural resources . However, Si anodes undergo a significant volume change (∼300%) during the lithiation/delithiation process, − leading to internal stress and various problems with active substance falling off the collector, instability of the solid electrolyte interface (SEI) layer, failure of the electrical connection between the active substance and the collector, and a decrease in battery capacity, conductivity, and cycle life. − To address these issues, many excellent studies have been reported, including the preparation of Si nanoparticles, , nanorods, nanowires, and nanotubes, the development of active-inertia systems, and the construction of porous structures. ,− Among these, reducing the particle size can stabilize the performance of Si anodes, but significant internal stress accumulates during multiple charges and discharges, eventually leading to battery failure. In contrast, the construction of porous structures can better stabilize the performance of Si anodes. − For example, Sohn et al prepared nonporous and porous micrometer-sized Si/C composite anodes by ball milling and alkaline etching .…”

Progress in Simulating The Effect of Stress on The Performance of Lithium/Sodium‐Based Batteries

“…prepared the heterogeneous structure 3D‐HNP‐Cu x O@m‐Cu by a simple three‐step method. [ 114 ] In the long cycle performance test, it can be seen that 3D‐HNP showed excellent electrochemical performance, and the battery capacity did not show substantial decline during the 200 cycles of charging and discharging. Core‐shell structure as the control group 3D‐NPCS‐CuxO@m‐Cu showed poor performance ( Figure ).…”

“…Reproduced with permission. [ 114 ] Copyright 2022, Wiley. b) Synthesis of layered VS 2 /MoS 2 heterostructures.…”

“…[107] Compared with the two structures discussed in the above chapter, heterogeneous structures can provide stronger interfacial links and more interfacial ion channels. [108] This provides a new way to solve the volume strain and the attenuation of electrode capacity caused by the intense [114] Copyright 2022, Wiley. b) Synthesis of layered VS 2 /MoS 2 heterostructures.…”