Unlocking Rapid Charging and Extended Lifetimes for Li-Ion Batteries Using Freestanding Quantum Conversion-Type Aerofilm Anode

Abstract

Batteries capable of quick charging as fast as fossil fuel vehicles are becoming a vital issue in the electric vehicle market. However, conversion-type materials promising as a next-generation anode have many problems to satisfy fast charging and long-term cycles due to their low conductivity and large irreversibility despite a high theoretical capacity. Here, we report effective strategies for a SnO2-based anode to enable rapid-charging, long-cycle, and high reversible capacity. The quantum size of SnO2 nanoparticles uniformly embedded within a 3D conductive carbon matrix as a prerequisite for high reversible capacity increases the interdiffusion layer and facilitates a highly reversible conversion reaction between Li2O/Sn and SnO2. In particular, the Sn–C chemical bond achieves ion-site control and direct electron transfer, enabling boost charging. Further, the robust and porous structure of the binder-free three-dimensional electrode buffers the massive volume expansion during Li insertion/desertion and allows for multidimensional rapid-ion diffusion. As a result, our quantum SnO2 anode delivers a high reversible capacity of about 753 mAh g–1 with a 468% capacity increase after 4000 cycles at 10 C. It also presents a gradually increasing capacity up to 548 mAh g–1 even at 20 C and superior cyclability over 20 000 cycles in capacity stabilization. This study will contribute to designing aerofilm-based conversion-type electrodes for fast charging devices.

Chemically engineered alloy anode enabling fully reversible conversion reaction: design of a C–Sn-bonded aerofilm anode

“…3,4,8,14–16,25,32,36,37,40 The aerofilm CNT–SnO 2 anode reported earlier showed an increase in capacity, whereas G–SnO 2 showed stable capacity at 0.2C and mild fading at 1C. 41 As determined from the SEI and structural chemistries, the dimensional properties of CNTs (1D) and graphene (2D) had an influential role on the electrochemical performance. 42 The 2D graphene sheets undergo Li intercalation (however, the majority of the capacity is from Sn) only at the edge sites rather than on the basal plane, which results in damages to the edge in the form of abnormal SEI growth and a hindered ion pathway that manifests as capacity fade in G–SnO 2 upon prolonged cycling.…”

Temperature-dependent synthesis of SnO2 or Sn embedded in hollow porous carbon nanofibers toward customized lithium-ion batteries

“…2f), the C-N bond proved the nitrogen atoms were doped into the carbon nanofiber, and the Sn-C bond indicated the electronic coupling among the SnO 2 nanodots, Sn nanoclusters, and HPCNFs after high-temperature annealing. The Sn-C chemical bonds in SnO 2 @HPCNFs and Sn@HPCNFs improved the structural stabilization of Sn-based electrodes and prevented their coarsening during repeated volume expansion/shrinking [61,62]. The N 1s peaks of SnO 2 @HPCNFs and Sn@HPCNFs could be resolved into three peaks (Fig.…”

Ultrafast Carbothermal Shock Synthesis of Wadsley–Roth Phase Niobium‐Based Oxides for Fast‐Charging Lithium‐Ion Batteries

“…These issues elevate the risk of thermal runaway and pose significant safety concerns. [2][3][4][5][6][7][8] Additionally, the inherently slow Li + ion diffusion kinetics in graphite further limits its rate performance. [9,10] Therefore, there is a pressing need to develop alternative anode materials that offer both higher lithiation potentials and faster Li + ion diffusion coefficients, without sacrificing capacity or cycling stability.…”