Solid-State Battery Anode Structure for Dendrite-Free Li Alloying
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Solution Overview
Problem
Existing all-solid-state lithium batteries suffer from low charge/discharge efficiency due to dendrite-induced short circuits, despite the inclusion of a Li storage layer made of carbon material and resin to inhibit such circuits.
Innovation Solution
An all-solid-state battery design utilizing a precipitation-dissolution reaction of metallic lithium, featuring a negative electrode current collector, a Li storage layer with fibrous carbon and resin, a metal M layer capable of alloying with lithium, and a solid electrolyte layer, which includes a Li-M alloy layer formed through initial charge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a Li storage layer made of carbon material and resin is added to inhibit dendrite-induced short circuits, then reliability is improved, but charge/discharge efficiency deteriorates
Solution Approach 1:
The patent employs a composite negative electrode structure combining carbon material (for dendrite inhibition), resin (for structural integrity), and metal M (for enhanced lithium alloying and charge/discharge efficiency). This multi-material composite approach resolves the contradiction by integrating the beneficial properties of each material while mitigating their individual limitations.
Solution Approach 2:
The invention introduces a specific metal M layer (where M is Mg, Al, Si, or Zn) with thickness of 1 nm to 10 μm at the interface between the Li storage layer and solid electrolyte. This localized enhancement of lithium alloying capability at the critical interface region improves charge/discharge efficiency without compromising the overall dendrite prevention function of the carbon-resin composite structure.
2Reliability
If a Li storage layer with carbon material and resin is used to improve reversible capacity, then reliability is improved, but charge/discharge efficiency deteriorates
Solution Approach 1:
The composite negative electrode comprising carbon material, resin, and metal M layer creates a synergistic structure where carbon provides reversible lithium storage capacity, resin maintains structural stability, and metal M enhances charge transfer kinetics. This composite approach simultaneously achieves high reversible capacity and improved charge/discharge efficiency.
Solution Approach 2:
The metal M layer acts as an intermediary between the carbon-based Li storage layer and the solid electrolyte, facilitating lithium ion transport and improving interfacial contact. This intermediary layer resolves the inefficiency caused by direct carbon-resin contact with the solid electrolyte, thereby improving charge/discharge efficiency while preserving reversible capacity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design significantly enhances charge/discharge efficiency by inhibiting short circuits and enabling reversible solubility of metallic lithium, resulting in improved battery performance.
Implementation Method 1
a metal M layer containing a metal M capable of being alloyed with lithium
Implementation Method 2
an all-solid-state battery that utilizes a precipitation-dissolution reaction of metallic lithium as a reaction of a negative electrode
Data Source
AI summary
Provided is an all-solid-state battery that utilizes a precipitation-dissolution reaction of metallic lithium as a reaction of a negative electrode. The all-solid-state battery has a negative electrode current collector, a Li storage layer containing a fibrous carbon material and a resin, a metal M layer capable of being alloyed with lithium, a solid electrolyte layer, and a positive electrode layer in this order.