Breaking the Graphite Trilemma: An Isotropic Core–Shell Anode for High-Energy and Fast-Charging Li-Ion Batteries
High-energy-density Li-ion batteries demand highly graphitized graphite anodes, yet elevated graphitization inevitably amplifies structural anisotropy, obstructing Li+ intercalation and compromising rate capability. To resolve this trilemma, we establish a precursor–structure–performance framework for pitch-based artificial graphites, revealing that this performance trade-off is governed by impurity content, ordered domains, and micropores: low-impurity precursors facilitate crystallite growth along the c-axis to realize high graphitization; ordered domains promote in-plane crystallite growth; and intrinsic micropores restrain excessive in-plane crystallite enlargement, lowering the orientation index and maintaining structural isotropy. Purified coal-based needle coke emerges as the optimal matrix, featuring a high graphitization degree of 94.89% alongside a moderate orientation index of 10.25. A resin-derived hard-carbon coating, with markedly higher disorder than its pitch-derived counterpart, is applied to construct an isotropic core–shell architecture (AG-R). The disordered surface layer acts as a Li+ transfer station, preserving low-rate capacity while boosting the Li+ diffusion coefficient by ~2.2-fold. In 2.5 Ah 18,650 full cells, AG-R achieves an energy density exceeding 430 Wh kg−1 (based on the total active material mass), retains 92.3% capacity at 10 C discharge and 81.6% at 3 C charge, and sustains over 80% capacity retention after 4600 cycles at 1 C. This work validates that precursor-directed bulk isotropy regulation, coupled with surface disordering engineering, offers a viable pathway toward fast-charging, high-energy graphite anodes.
Authors
- Liekai Liu (ORCID: https://orcid.org/0000-0003-0748-5947)
- Keju Ding
- Wenliang Hu
- Bing Kang
- Siqi Liu
- Yongcheng Zou
Institutions
- Jiangxi University of Water Resources and Electric Power (CN)
Publication Details
- Journal
- Batteries
- Published
- 2026-10-13
- DOI
- https://doi.org/10.3390/batteries12100422
- Primary Topic
- Advancements in Battery Materials
- Type
- article
- Field-Weighted Citation Impact
- 0.00