Lack of antecedent basis in claims

CAFC rules that Energizer's patent (US 5464709) is not invalid and complies with 35 USC 112. Energizer Holdings, Inc., et al. v. International Trade Commission, et al.

The '709 patent is for an electrolytic alkaline battery cell that is substantially free of mercury.
Claim 1 of '709 patent reads:

1. An electrochemical cell comprising an alkaline electrolyte, a cathode comprising manganese dioxide as an active cathode component, and an anode gel comprised of zinc as the active anode component, wherein the cell contains less than 50 parts of mercury per million parts by weight of the cell and said zinc anode has a gel expansion of less than 25% after being discharged for 161 minutes to 15% depth of discharge at 2.88A.

ITC argues that there is no antecedent basis for "said zinc anode" in claim 1.
However, CAFC relies on Slimfold and states that "an antecedent basis can be presented by implication." Then CAFC concludes that "anode gel" is by implication the antecedent basis for "said" zinc anode.

I think the claim 1 can be amended by replacing "...said zinc anode has a gel expansion of less than..." with "...an expansion of the anode gel comprised of zinc is less than..." to avoid the antecedent basis issue. JWP